Security Bulletin
Summary
There are mulitple vulnerabilities in the RESTEasy and Apache CXF library that affect IBM WebSphere Application Server Liberty with the restfulWS-3.0, restfulWS-3.1, restfulWS-4.0, jaxrs-2.0, jaxrs-2.1, jaxws-2.2, xmlWS-3.0 or xmlWS-4.0 enabled.
Vulnerability Details
CVEID: CVE-2026-89058
DESCRIPTION: A flaw was found in RESTEasy's CorsFilter, which, when configured to allow all origins ("*"), reflects the request's Origin header back in the Access-Control-Allow-Origin response together with Access-Control-Allow-Credentials: true. This permissive cross-origin policy allows a malicious website to make credentialed cross-origin requests and read authenticated responses from a victim's session, resulting in a loss of confidentiality.
CWE: CWE-942: Permissive Cross-domain Security Policy with Untrusted Domains
CVSS Source: secalert@redhat.com
CVSS Base score: 7.4
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N)
CVEID: CVE-2026-89059
DESCRIPTION: A flaw was found in RESTEasy's IIOImageProvider, which decodes attacker-supplied image request bodies without enforcing any limit on the declared image dimensions or pixel count. A remote, unauthenticated attacker can send a small crafted image declaring enormous dimensions to trigger a very large memory allocation, exhausting the JVM heap and resulting in a denial of service.
CWE: CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)
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-2026-108039
DESCRIPTION: By default, StaxUtils placed no limit on the total number of elements or the total number of characters in an XML document. A very large request could therefore use a lot of memory and CPU during parsing, especially where CXF builds a DOM from the input (for example SAAJ or WS-Security), and could cause a denial of service when no request size limit was configured. Both limits now have defaults: the maximum element count is 100 × maxChildElements (5,000,000 by default), and the maximum document size is 256M characters. Applications that process larger documents can raise the limits with the org.apache.cxf.stax.maxElementCount and org.apache.cxf.stax.maxXMLCharacters properties.
Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.
CWE: CWE-776: Improper Restriction of Recursive Entity References in DTDs
CVSS Source: CISA ADP
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-2026-107937
DESCRIPTION: In Apache CXF, the parser for multipart/MTOM attachment part headers did not fully enforce the configured attachment-max-header-size (default 300 characters) and attachment-headers-max-count (default 500) limits. The size limit was applied only to each physical line, not to a header value built from continuation lines or to the combined values of a repeated header. The count limit was checked against the number of distinct header names, not the total number of header lines. A remote, unauthenticated attacker could send a multipart request with very large folded or repeated part headers. The server would then allocate memory without bound, causing a denial of service.
Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: CISA ADP
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-2026-78384
DESCRIPTION: CompressionUtils.inflate() decompressed attacker-controlled DEFLATE data with no output-size cap. A small (~KB) crafted payload could expand to gigabytes on the heap. Reachable via JWE decryption when zip=DEF (e.g. JoseSessionTokenProvider with RSA-OAEP key wrap) and via SAML redirect/POST binding token inflation — in both cases decompression happens before/independent of trust validation.
Fix: Added a configurable maximum inflated-size cap (default 10 MiB, org.apache.cxf.compression-max-inflated-size system property) to CompressionUtils.inflate(); aborts with DataFormatException once exceeded.
Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.
CWE: CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)
CVSS Source: CISA ADP
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)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| WebSphere Application Server - Liberty | 17.0.0.3 - 26.0.0.11 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by applying a currently available interim fix or fix pack that contains the fix for APAR DT505285. To determine if a feature is enabled for IBM WebSphere Application Server Liberty, refer to How to determine if Liberty is using a specific feature.
For IBM WebSphere Application Server Liberty 17.0.0.3 - 26.0.0.11 using the restfulWS-3.0, restfulWS-3.1, restfulWS-4.0, jaxrs-2.0, jaxrs-2.1, jaxws-2.2, xmlWS-3.0 or xmlWS-4.0 feature(s):
· Upgrade to minimal fix pack levels as required by the interim fix and then apply the Interim Fix that resolves DT505285
--OR--
· Apply Liberty Fix Pack 26.0.0.12 or later (targeted availability 4Q2026).
Additional interim fixes may be available and linked off the interim fix download page.
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
To determine if a feature is enabled for IBM WebSphere Application Server Liberty, refer to How to determine if Liberty is using a specific feature.
Acknowledgement
Change History
03 Nov 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:
05 November 2026
Initial Publish date:
03 November 2026
UID
ibm17295357