Security Bulletin
Summary
IBM Rational Developer for i is affected by a sensitive information exposure vulnerability in Eclipse Jetty-server (CVE-2026-10051), an improper input validation vulnerability in Eclipse Jetty-server (CVE-2026-6790), an authorization decision vulnerability in Eclipse Jetty-util (CVE-2026-8384), an improper handling of alternate encoding vulnerability in Jetty-security (CVE-2026-10050), an overflow vulnerability in Immutable (CVE-2026-59879), and an inefficient algorithmic complexity vulnerability in Immutable (CVE-2026-59880) as described in the vulnerability details section.
Vulnerability Details
CVEID: CVE-2026-10050
DESCRIPTION: In Eclipse Jetty, the Digest authentication server-side component uses ISO-8859-1 to encode the password as bytes.
This was done because the initial specification for HTTP did not specify explicitly a charset, and it was assumed to be ISO-8859-1 for historical reasons.
If the password contains characters that cannot be represented in ISO-8859-1, they are silently replaced by `?`. This happens with passwords that contain Chinese, Cyrillic or Greek characters, for example: `αβ123` converts to `??123`.
An attacker can send a request with a digest `Authorization` header crafted with a password made of only `?` characters; the server would match any password of the same length that contains non-ISO-8859-1 characters.
Recent HTTP Digest [RFC-7616](https://datatracker.ietf.org/doc/html/rfc7616) supports a `charset` parameters that defaults to UTF-8 that allows for correct encoding/decoding of passwords.
CWE: CWE-173: Improper Handling of Alternate Encoding
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-2026-59879
DESCRIPTION: Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, List#set, List#setSize, List#setIn, List#updateIn, and the functional set, setIn, and updateIn mishandle an index or size in the range 2 ** 30 to 2 ** 31 in setListBounds in src/List.js, causing an empty List to enter an uncatchable infinite loop, a populated List to allocate without bound until process abort, or setSize to silently wrap large values. This issue is fixed in versions 4.3.9 and 5.1.8.
CWE: CWE-190: Integer Overflow or Wraparound
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-2026-59880
DESCRIPTION: Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, Immutable.Map and Immutable.Set keep keys that share the same 32-bit hash in a HashCollisionNode collision bucket that is scanned linearly, allowing an attacker who controls keys inserted into a Map, such as through Immutable.Map(obj), Immutable.fromJS(obj), state.merge(userObject), or mergeDeep, to craft many colliding keys and degrade insertion and lookup to consume disproportionate CPU. This issue is fixed in versions 4.3.9 and 5.1.8.
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-2026-10051
DESCRIPTION: In Eclipse Jetty, a first HTTP/1.1 request with trailers causes the server to retain the trailers in subsequent requests performed over the same connection.
Subsequent request that do not have trailers report the trailers of the first request.
Subsequent request that do have trailers report the union of trailers of the first request and the current request.
CWE: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
CVSS Source: NVD
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-2026-6790
DESCRIPTION: In Eclipse Jetty, for HTTP/1, HTTP/2 and HTTP/3 requests, there is no strict check that the request authority (host and port) matches what provided in the Host header (if present).
This was not enforced in earlier HTTP RFC (for example, in RFC 2616), but it is in the latest RFC (9110 and 9112).
This mismatch can cause a number of problems that may be classified as vulnerabilities such as:
*
URI constructions (for example, for redirects -- this is typical for login pages)
*
Virtual host selection
*
Reverse proxying
*
Misleading logs
*
Etc.
Given that the latest RFCs require that request authority and Host header must match, Jetty should enforce this invariant.
CWE: CWE-20: Improper Input Validation
CVSS Source: emo@eclipse.org
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-2026-8384
DESCRIPTION: In Eclipse Jetty, an HTTP URI of this form:
/public;/../admin/secret.txt
results in an unresolved path of:
/public/../admin/secret.txt
instead of the expected:
/admin/secret.txt
Jetty itself is not affected, as it will not serve the secret.txt file because it will not pass the alias checker (only resolved resources are served).
However, web applications that rely on resolved paths being provided by Jetty may be confused when receiving an unresolved path.
CWE: CWE-647: Use of Non-Canonical URL Paths for Authorization Decisions
CVSS Source: emo@eclipse.org
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)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| RDi | 9.9 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now.
| Products(s) | Versions(s) | Remediation/Fix/Instructions |
| IBM Rational Developer for i | 9.9.0.0 - 9.9.0.4 |
Interim fix 9.9.0.5 for IBM Rational Developer for i is available. Use 'Help>Check for Updates' from within the product to install the fix. Alternatively, the fix is available at Downloads. Install the downloaded update:
|
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
14 Aug 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
Was this topic helpful?
Document Information
Modified date:
14 August 2026
Initial Publish date:
14 August 2026
UID
ibm17283864