Security Bulletin
Summary
IBM Guardium Data Protection has addressed these vulnerabilities in an update.
Vulnerability Details
CVEID: CVE-2026-18477
DESCRIPTION: A TOCTOU (Time-of-Check Time-of-Use) vulnerability in GNU tar's incremental dumpdir 'X' rename handling allows a local attacker with write access to a directory being backed up to influence the restore process if the attacker has access to the system where the restore is being performed. During restoration, files or directories may be created, renamed or overwritten outside the intended extraction directory. This could lead to unauthorized file modification or, in some cases, privilege escalation. Exploitation does not require the attacker to modify or craft the archive, and standard backup and restore workflows—including extracting into a newly created directory without using the -P option do not mitigate the issue.
CWE: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
CVSS Source: secalert@redhat.com
CVSS Base score: 4.4
CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:N)
CVEID: CVE-2026-18508
DESCRIPTION: A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.
CWE: CWE-59: Improper Link Resolution Before File Access ('Link Following')
CVSS Source: secalert@redhat.com
CVSS Base score: 4.4
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N)
CVEID: CVE-2026-5704
DESCRIPTION: A flaw was found in tar. A remote attacker could exploit this vulnerability by crafting a malicious archive, leading to hidden file injection with fully attacker-controlled content. This bypasses pre-extraction inspection mechanisms, potentially allowing an attacker to introduce malicious files onto a system without detection.
CWE: CWE-434: Unrestricted Upload of File with Dangerous Type
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N)
CVEID: CVE-2026-50560
DESCRIPTION: Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
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-2026-47244
DESCRIPTION: Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, DefaultHttp2Connection.DefaultEndpoint initialises maxActiveStreams/maxStreams to Integer.MAX_VALUE, and Http2Settings never inserts SETTINGS_MAX_CONCURRENT_STREAMS by default (Http2Settings.java:305-307 only clamps a user-supplied value). Unless the application explicitly calls initialSettings().maxConcurrentStreams(n), a Netty HTTP/2 server advertises no limit and enforces none locally. Each open stream allocates a DefaultStream object, PropertyMap slots, flow-controller state and IntObjectHashMap entry; with ~2^30 permissible odd stream IDs a single TCP connection can create hundreds of thousands of long-lived stream objects. This is also the precondition for CVE-2023-44487-style Rapid-Reset amplification, where the absence of a low concurrent cap multiplies backend work. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
CWE: CWE-400: Uncontrolled Resource Consumption
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:N/A:L)
CVEID: CVE-2026-48043
DESCRIPTION: Netty is a network application framework for development of protocol servers and clients. In netty-codec-http2 prior to versions 4.1.135.Final and 4.2.15.Final, the `DelegatingDecompressorFrameListener` class orchestrates HTTP/2 decompression by embedding a per-stream `EmbeddedChannel` that runs the appropriate decompression codec (gzip, deflate, zstd) and forwards decompressed chunks to a wrapped listener. Each decompressed chunk is a pooled `ByteBuf` handed to an anonymous `ChannelInboundHandlerAdapter` tail handler, which becomes the sole owner responsible for releasing it. A remote peer could send frames that would result in the flow-controller throwing and so trigger a resource leak which at the end might take down the whole JVM due OOME. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
CWE: CWE-400: Uncontrolled Resource Consumption
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-2026-45673
DESCRIPTION: Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's DNS resolver uses a predictable PRNG for generating DNS transaction IDs and defaults to a static UDP source port. This combination reduces the entropy of DNS queries, enabling DNS Cache Poisoning (Kaminsky attack). Versions 4.1.135.Final and 4.2.15.Final patch the issue.
CWE: CWE-330: Use of Insufficiently Random Values
CVSS Source: security-advisories@github.com
CVSS Base score: 6.8
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N)
CVEID: CVE-2026-45674
DESCRIPTION: Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's DnsResolveContext fails to validate the origin (bailiwick) of CNAME records in DNS responses. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
CWE: CWE-345: Insufficient Verification of Data Authenticity
CVSS Source: NVD
CVSS Base score: 10
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N)
CVEID: CVE-2026-47691
DESCRIPTION: Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's `DnsResolveContext` insufficiently validates the bailiwick of NS records, enabling DNS Cache Poisoning. An attacker controlling an authoritative name server for a subdomain can poison the cache for parent domains (like `.co.uk`). In `io.netty.resolver.dns.DnsResolveContext.AuthoritativeNameServerList#add` method accepts any NS record from the AUTHORITY section as long as the record's name is a suffix of the questionName. Subsequently, the `handleWithAdditional` method caches the associated A records from the ADDITIONAL section directly into the `authoritativeDnsServerCache` under the parent domain's key. This bypasses standard bailiwick rules, where a server authoritative for a subdomain should not be trusted to provide authoritative records for its parent. The poisoned cache is then used for all future resolutions under the parent domain's key. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
CWE: CWE-345: Insufficient Verification of Data Authenticity
CVSS Source: NVD
CVSS Base score: 10
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| IBM Guardium Data Protection | 12.2.3 |
| IBM Guardium Data Protection | 12.1 |
Remediation/Fixes
IBM encourages customers to update their systems promptly.
| Product | Versions | Fix |
| IBM Guardium Data Protection | 12.2.3 | https://www.ibm.com/support/fixcentral/swg/quickorder?parent=IBM%20Security&product=ibm/Information+Management/InfoSphere+Guardium&release=All&platform=All&function=fixId&fixids=SqlGuard_12.0p237_FixPack&includeSupersedes=0&source=fc |
| IBM Guardium Data Protection | 12.1 |
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
20 Oct 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:
20 October 2026
Initial Publish date:
20 October 2026
UID
ibm17293137