Security Bulletin
Summary
Multiple vulnerabilities were addressed in IBM Observability with Instana within Instana Agent container image build 1.0.320
Vulnerability Details
CVEID: CVE-2026-42009
DESCRIPTION: A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.
CWE: CWE-475: Undefined Behavior for Input to API
CVSS Source: secalert@redhat.com
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-22016
DESCRIPTION: Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Java SE accessible data.
CWE: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
CVSS Source: secalert_us@oracle.com
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
CVEID: CVE-2026-34282
DESCRIPTION: Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Java SE.
CWE: CWE-400: Uncontrolled Resource Consumption
CVSS Source: secalert_us@oracle.com
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-42198
DESCRIPTION: pgjdbc is an open source postgresql JDBC Driver. From version 42.2.0 to before version 42.7.11, pgjdbc is vulnerable to a client-side denial of service during SCRAM-SHA-256 authentication. A malicious server can instruct the driver to perform SCRAM authentication with a very large iteration count. With a large enough value, the client spends an unbounded amount of CPU time inside PBKDF2 before authentication can fail. A single attempt ties up a CPU core. Repeated or concurrent attempts exhaust client CPU and can wedge connection pools. In affected versions, loginTimeout did not fully mitigate this problem. When loginTimeout expired, the caller could stop waiting, but the worker thread performing the connection attempt could continue running and burning CPU inside the SCRAM PBKDF2 computation. This issue has been patched in version 42.7.11.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: security-advisories@github.com
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-39836
DESCRIPTION: The Dial and LookupPort functions panic on Windows when provided with an input containing a NUL (0).
CWE: CWE-476: NULL Pointer Dereference
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-42010
DESCRIPTION: A flaw was found in gnutls. Servers configured with RSA-PSK (Rivest–Shamir–Adleman – Pre-Shared Key) wrongfully matched usernames containing a NUL character with truncated usernames. A remote attacker could exploit this by sending a specially crafted username, leading to an authentication bypass. This vulnerability allows an attacker to gain unauthorized access by circumventing the authentication process.
CWE: CWE-170: Improper Null Termination
CVSS Source: NVD
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-35204
DESCRIPTION: Helm is a package manager for Charts for Kubernetes. From 4.0.0 to 4.1.3, a specially crafted Helm plugin, when installed or updated, will cause Helm to write the contents of the plugin to an arbitrary filesystem location. To prevent this, validate that the plugin.yaml of the Helm plugin does not include a version: field containing POSIX dot-dot path separators ie. "/../". This vulnerability is fixed in 4.1.4.
CWE: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVSS Source: NVD
CVSS Base score: 8.6
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H)
CVEID: CVE-2026-35205
DESCRIPTION: Helm is a package manager for Charts for Kubernetes. From 4.0.0 to 4.1.3, Helm will install plugins missing provenance (.prov file) when signature verification is required. This vulnerability is fixed in 4.1.4.
CWE: CWE-636: Not Failing Securely ('Failing Open')
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-45186
DESCRIPTION: In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.
CWE: CWE-407: Inefficient Algorithmic Complexity
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-39979
DESCRIPTION: jq is a command-line JSON processor. In commits before 2f09060afab23fe9390cce7cb860b10416e1bf5f, the jv_parse_sized() API in libjq accepts a counted buffer with an explicit length parameter, but its error-handling path formats the input buffer using %s in jv_string_fmt(), which reads until a NUL terminator is found rather than respecting the caller-supplied length. This means that when malformed JSON is passed in a non-NUL-terminated buffer, the error construction logic performs an out-of-bounds read past the end of the buffer. The vulnerability is reachable by any libjq consumer calling jv_parse_sized() with untrusted input, and depending on memory layout, can result in memory disclosure or process termination. The issue has been patched in commit 2f09060afab23fe9390cce7cb860b10416e1bf5f.
CWE: CWE-125: Out-of-bounds Read
CVSS Source: NVD
CVSS Base score: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L)
CVEID: CVE-2026-40164
DESCRIPTION: jq is a command-line JSON processor. Before commit 0c7d133c3c7e37c00b6d46b658a02244fdd3c784, jq used MurmurHash3 with a hardcoded, publicly visible seed (0x432A9843) for all JSON object hash table operations, which allowed an attacker to precompute key collisions offline. By supplying a crafted JSON object (~100 KB) where all keys hashed to the same bucket, hash table lookups degraded from O(1) to O(n), turning any jq expression into an O(n²) operation and causing significant CPU exhaustion. This affected common jq use cases such as CI/CD pipelines, web services, and data processing scripts, and was far more practical to exploit than existing heap overflow issues since it required only a small payload. This issue has been patched in commit 0c7d133c3c7e37c00b6d46b658a02244fdd3c784.
CWE: CWE-328: Use of Weak Hash
CVSS Source: security-advisories@github.com
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-26740
DESCRIPTION: Buffer Overflow vulnerability in giflib v.5.2.2 allows a remote attacker to cause a denial of service via the EGifGCBToExtension overwriting an existing Graphic Control Extension block without validating its allocated size.
CWE: CWE-787: Out-of-bounds Write
CVSS Source: CISA ADP
CVSS Base score: 8.2
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H)
CVEID: CVE-2026-25646
DESCRIPTION: LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.55, an out-of-bounds read vulnerability exists in the png_set_quantize() API function. When the function is called with no histogram and the number of colors in the palette is more than twice the maximum supported by the user's display, certain palettes will cause the function to enter into an infinite loop that reads past the end of an internal heap-allocated buffer. The images that trigger this vulnerability are valid per the PNG specification. This vulnerability is fixed in 1.6.55.
CWE: CWE-122: Heap-based Buffer Overflow
CVSS Source: NVD
CVSS Base score: 8.1
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-66293
DESCRIPTION: LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.52, an out-of-bounds read vulnerability in libpng's simplified API allows reading up to 1012 bytes beyond the png_sRGB_base[512] array when processing valid palette PNG images with partial transparency and gamma correction. The PNG files that trigger this vulnerability are valid per the PNG specification; the bug is in libpng's internal state management. Upgrade to libpng 1.6.52 or later.
CWE: CWE-125: Out-of-bounds Read
CVSS Source: security-advisories@github.com
CVSS Base score: 7.1
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H)
CVEID: CVE-2026-41417
DESCRIPTION: Netty allows request-line validation to be bypassed when a `DefaultHttpRequest` or `DefaultFullHttpRequest` is created first and its URI is later changed via `setUri()`. The constructors reject CRLF and whitespace characters that would break the start-line, but `setUri()` does not apply the same validation. `HttpRequestEncoder` and `RtspEncoder` then write the URI into the request line verbatim. If attacker-controlled input reaches `setUri()`, this enables CRLF injection and insertion of additional HTTP or RTSP requests, leading to HTTP request smuggling or desynchronization on the HTTP side and request injection on the RTSP side. This issue is fixed in versions 4.2.13.Final and 4.1.133.Final.
CWE: CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')
CVSS Source: security-advisories@github.com
CVSS Base score: 5.3
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
CVEID: CVE-2025-14813
DESCRIPTION: : Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcprov on all (core modules).
This vulnerability is associated with program files G3413CTRBlockCipher.
This issue affects BC-JAVA: from 1.59 before 1.80.2, from 1.81 before 1.81.1, from 1.82 before 1.84.
CWE: CWE-327: Use of a Broken or Risky Cryptographic Algorithm
CVSS Source: bcorg
CVSS Base score: 9.3
CVSS Vector: (CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:M/U:Red)
CVEID: CVE-2026-5598
DESCRIPTION: Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules).
This vulnerability is associated with program files FrodoEngine.Java.
This issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.81.1, from 1.82 before 1.84.
CWE: CWE-385: Covert Timing Channel
CVSS Source: bcorg
CVSS Base score: 8.9
CVSS Vector: (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:P/AU:Y/R:X/V:X/RE:X/U:Red)
CVEID: CVE-2026-29181
DESCRIPTION: OpenTelemetry-Go is the Go implementation of OpenTelemetry. From 1.36.0 to 1.40.0, multi-value baggage: header extraction parses each header field-value independently and aggregates members across values. This allows an attacker to amplify cpu and allocations by sending many baggage: header lines, even when each individual value is within the 8192-byte per-value parse limit. This vulnerability is fixed in 1.41.0.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: security-advisories@github.com
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-1002
DESCRIPTION: The Vert.x Web static handler component cache can be manipulated to deny the access to static files served by the handler using specifically crafted request URI.
The issue comes from an improper implementation of the C. rule of section 5.2.4 of RFC3986 and is fixed in Vert.x Core component (used by Vert.x Web): https://github.com/eclipse-vertx/vert.x/pull/5895
Steps to reproduce
Given a file served by the static handler, craft an URI that introduces a string like bar%2F..%2F after the last / char to deny the access to the URI with an HTTP 404 response. For example https://example.com/foo/index.html can be denied with https://example.com/foo/bar%2F..%2Findex.html
Mitgation
Disabling Static Handler cache fixes the issue.
StaticHandler staticHandler = StaticHandler.create().setCachingEnabled(false);
CWE: CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
CVSS Source: NVD
CVSS Base score: 5.3
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
CVEID: CVE-2026-22737
DESCRIPTION: Use of Java scripting engine enabled (e.g. JRuby, Jython) template views in Spring MVC and Spring WebFlux applications can result in disclosure of content from files outside the configured locations for script template views. This issue affects Spring Framework: from 7.0.0 through 7.0.5, from 6.2.0 through 6.2.16, from 6.1.0 through 6.1.25, from 5.3.0 through 5.3.46.
CWE: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVSS Source: security@vmware.com
CVSS Base score: 5.9
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)
CVEID: CVE-2026-5588
DESCRIPTION: Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules), Legion of the Bouncy Castle Inc. BCPKIX-FIPS bcpkix on All (pkix modules), Legion of the Bouncy Castle Inc. BCPIX-LTS bcpkix on All (pkix modules).
This vulnerability is associated with program files JcaContentVerifierProviderBuilder.Java, JcaContentVerfierProviderBuilder.Java.
This issue affects BC-JAVA: from 1.67 before 1.80.2, from 1.81 before 1.81.1, from 1.82 before 1.84; BCPKIX-FIPS: from 2.0.6 before 2.0.11, from 2.1.7 before 2.1.11; BCPIX-LTS: from 2.73.7 before 2.73.11.
CWE: CWE-327: Use of a Broken or Risky Cryptographic Algorithm
CVSS Source: Chrome
CVSS Base score: 6.3
CVSS Vector: (CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber)
CVEID: CVE-2026-0636
DESCRIPTION: Improper neutralization of special elements used in an LDAP query ('LDAP injection') vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcprov on all (prov modules).
This vulnerability is associated with program files LDAPStoreHelper.
This issue affects BC-JAVA: from 1.74 before 1.80.2, from 1.81 before 1.81.1, from 1.82 before 1.84.
CWE: CWE-90: Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
CVSS Source: bcorg
CVSS Base score: 5.5
CVSS Vector: (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/S:N/AU:Y/R:A/RE:M/U:Amber)
CVEID: CVE-2026-22745
DESCRIPTION: Spring MVC and WebFlux applications are vulnerable to Denial of Service attacks when resolving static resources.
More precisely, an application can be vulnerable when all the following are true:
* the application is using Spring MVC or Spring WebFlux
* the application is serving static resources from the file system
* the application is running on a Windows platform
When all the conditions above are met, the attacker can send malicious requests that are slow to resolve and that can keep HTTP connections in use. This can cause a Denial of Service on the application.
CWE: CWE-400: Uncontrolled Resource Consumption
CVSS Source: security@vmware.com
CVSS Base score: 5.3
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
CVEID: CVE-2026-22740
DESCRIPTION: A WebFlux server application that processes multipart requests creates temp files for parts larger than 10 K. Under some circumstances, temp files may remain not deleted after the request is fully processed. This allows an attacker to consume available disk space.
Older, unsupported versions are also affected.
CWE: CWE-400: Uncontrolled Resource Consumption
CVSS Source: security@vmware.com
CVSS Base score: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-34477
DESCRIPTION: The fix for CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j… system property, but not when configured through the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslC… attribute of the Ssl element.
Although the verifyHostName configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value.
A network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met:
* An SMTP, Socket, or Syslog appender is in use.
* TLS is configured via a nested Ssl element.
* The attacker can present a certificate issued by a CA trusted by the appender's configured trust store, or by the default Java trust store if none is configured.
This issue does not affect users of the HTTP appender, which uses a separate verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#Http… attribute that was not subject to this bug and verifies host names by default.
Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.
CWE: CWE-297: Improper Validation of Certificate with Host Mismatch
CVSS Source: NVD
CVSS Base score: 5.9
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N)
CVEID: CVE-2026-22735
DESCRIPTION: Spring MVC and WebFlux applications are vulnerable to stream corruption when using Server-Sent Events (SSE). This issue affects Spring Foundation: from 7.0.0 through 7.0.5, from 6.2.0 through 6.2.16, from 6.1.0 through 6.1.25, from 5.3.0 through 5.3.46.
CWE: CWE-667: Improper Locking
CVSS Source: security@vmware.com
CVSS Base score: 2.6
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N)
CVEID: CVE-2026-22741
DESCRIPTION: Spring MVC and WebFlux applications are vulnerable to cache poisoning when resolving static resources.
More precisely, an application can be vulnerable when all the following are true:
* the application is using Spring MVC or Spring WebFlux
* the application is configuring the resource chain support https://docs.spring.io/spring-framework/reference/web/webmvc/mvc-config… with caching enabled
* the application adds support for encoded resources resolution
* the resource cache must be empty when the attacker has access to the application
When all the conditions above are met, the attacker can send malicious requests and poison the resource cache with resources using the wrong encoding. This can cause a denial of service by breaking the front-end application for clients.
CWE: CWE-524: Use of Cache Containing Sensitive Information
CVSS Source: security@vmware.com
CVSS Base score: 3.1
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L)
CVEID: CVE-2026-32283
DESCRIPTION: If one side of the TLS connection sends multiple key update messages post-handshake in a single record, the connection can deadlock, causing uncontrolled consumption of resources. This can lead to a denial of service. This only affects TLS 1.3.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-42327
DESCRIPTION: rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.7 to before 0.10.79, X509Ref::ocsp_responders returns OCSP responder URLs from a certificate's AIA extension as OpensslString, whose DerefTarget = str wraps the raw bytes with str::from_utf8_unchecked. OpenSSL does not enforce that the underlying IA5String is ASCII, so a certificate with non-UTF-8 bytes in its OCSP accessLocation causes safe Rust code to construct a &str that violates the UTF-8 invariant — resulting in undefined behavior. This vulnerability is fixed in 0.10.79.
CWE: CWE-20: Improper Input Validation
CVSS Source: security-advisories@github.com
CVSS Base score: 8.7
CVSS Vector: (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)
CVEID: CVE-2026-44662
DESCRIPTION: rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.10.0 to before 0.10.79, CipherCtxRef::cipher_update, CipherCtxRef::cipher_update_vec, and symm::Crypter::update incorrectly sized output buffers when used with AES key-wrap-with-padding ciphers (EVP_aes_{128,192,256}_wrap_pad). For a non-multiple-of-8 input, OpenSSL writes up to 7 bytes past the end of the caller's buffer or Vec, producing attacker-controllable heap corruption when the plaintext length is attacker-influenced. This only impacts users using AES key-wrap-with-padding ciphers. This vulnerability is fixed in 0.10.79.
CWE: CWE-122: Heap-based Buffer Overflow
CVSS Source: security-advisories@github.com
CVSS Base score: 5.1
CVSS Vector: (CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)
CVEID: CVE-2026-34478
DESCRIPTION: Apache Log4j Core's Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.html#RFC5424Layout , in versions 2.21.0 through 2.25.3, is vulnerable to log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes.
Two distinct issues affect users of stream-based syslog services who configure Rfc5424Layout directly:
* The newLineEscape attribute was silently renamed, causing newline escaping to stop working for users of TCP framing (RFC 6587), exposing them to CRLF injection in log output.
* The useTlsMessageFormat attribute was silently renamed, causing users of TLS framing (RFC 5425) to be silently downgraded to unframed TCP (RFC 6587), without newline escaping.
Users of the SyslogAppender are not affected, as its configuration attributes were not modified.
Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.
CWE: CWE-117: Improper Output Neutralization for Logs
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
CVEID: CVE-2026-34480
DESCRIPTION: Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets producing invalid XML output whenever a log message or MDC value contains such characters.
The impact depends on the StAX implementation in use:
* JRE built-in StAX: Forbidden characters are silently written to the output, producing malformed XML. Conforming parsers must reject such documents with a fatal error, which may cause downstream log-processing systems to drop the affected records.
* Alternative StAX implementations (e.g., Woodstox https://github.com/FasterXML/woodstox , a transitive dependency of the Jackson XML Dataformat module): An exception is thrown during the logging call, and the log event is never delivered to its intended appender, only to Log4j's internal status logger.
Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue by sanitizing forbidden characters before XML output.
CWE: CWE-116: Improper Encoding or Escaping of Output
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
CVEID: CVE-2026-34481
DESCRIPTION: Apache Log4j's JsonTemplateLayout https://logging.apache.org/log4j/2.x/manual/json-template-layout.html , in versions up to and including 2.25.3, produces invalid JSON output when log events contain non-finite floating-point values (NaN, Infinity, or -Infinity), which are prohibited by RFC 8259. This may cause downstream log processing systems to reject or fail to index affected records.
An attacker can exploit this issue only if both of the following conditions are met:
* The application uses JsonTemplateLayout.
* The application logs a MapMessage containing an attacker-controlled floating-point value.
Users are advised to upgrade to Apache Log4j JSON Template Layout 2.25.4, which corrects this issue.
CWE: CWE-116: Improper Encoding or Escaping of Output
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
CVEID: CVE-2026-34479
DESCRIPTION: The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.
Two groups of users are affected:
* Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file.
* Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class.
Users are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue.
Note: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the Log4j 1 to Log4j 2 migration guide https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html , and specifically the section on eliminating reliance on the bridge.
CWE: CWE-116: Improper Encoding or Escaping of Output
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
CVEID: CVE-2026-6860
DESCRIPTION: A TCP client can perform a TLS handshake and present the server name extension with a server name that is accepted by a server wildcard name, e.g. if the server is configured with a certificate accepting *.example.com, any XYZ.example.com where xyz is a valid name can be used.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: NVD
CVSS Base score: 5.3
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
CVEID: CVE-2026-33811
DESCRIPTION: When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.
CWE: CWE-415: Double Free
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-32281
DESCRIPTION: Validating certificate chains which use policies is unexpectedly inefficient when certificates in the chain contain a very large number of policy mappings, possibly causing denial of service. This only affects validation of otherwise trusted certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.
CWE: CWE-295: Improper Certificate Validation
CVSS Source: NVD
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-33846
DESCRIPTION: A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating that the message_length field remains consistent across all fragments of the same logical message. An attacker can exploit this by sending crafted DTLS fragments with conflicting message_length values, causing the implementation to allocate a buffer based on a smaller initial fragment and subsequently write beyond its bounds using larger, inconsistent fragments. Because the merge operation does not enforce proper bounds checking against the allocated buffer size, this results in an out-of-bounds write on the heap. The vulnerability is remotely exploitable without authentication via the DTLS handshake path and can lead to application crashes or potential memory corruption.
CWE: CWE-130: Improper Handling of Length Parameter Inconsistency
CVSS Source: secalert@redhat.com
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-33845
DESCRIPTION: A flaw in GnuTLS DTLS handshake parsing allows malformed fragments with zero length and non-zero offset, leading to an integer underflow during reassembly and resulting in an out-of-bounds read. This issue is remotely exploitable and may cause information disclosure or denial of service.
CWE: CWE-191: Integer Underflow (Wrap or Wraparound)
CVSS Source: NVD
CVSS Base score: 9.1
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H)
CVEID: CVE-2026-4878
DESCRIPTION: A flaw was found in libcap. A local unprivileged user can exploit a Time-of-check-to-time-of-use (TOCTOU) race condition in the `cap_set_file()` function. This allows an attacker with write access to a parent directory to redirect file capability updates to an attacker-controlled file. By doing so, capabilities can be injected into or stripped from unintended executables, leading to privilege escalation.
CWE: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
CVSS Source: NVD
CVSS Base score: 7
CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| IBM Observability with Instana (Agent) | Build 1.0.303 to 1.0.319 |
Remediation/Fixes
IBM strongly recommends addressing these vulnerabilities now by updating IBM Observability with Instana to the latest release as described here:
https://www.ibm.com/docs/en/instana-observability?topic=agents-updating-host
| Affected Product(s) | Version(s) | Remediation/Fixes/Instructions |
| IBM Observability with Instana (Agent) | Build 1.0.303 to 1.0.319 | Build 1.0.320 |
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
29 Jun 2026: Initial Publication
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.
Document Location
Worldwide
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Document Information
Modified date:
28 June 2026
Initial Publish date:
29 June 2026
UID
ibm17278304