CVE-2026-97791Apache CXF: STSTokenValidator can accept untrusted SAML assertions because it shares validation state between requests

Description

In Apache CXF, STSTokenValidator checks whether a SAML assertion is signed by a trusted certificate before deciding to send it to the STS. That result was stored in one object shared by all requests, so one request could read another's result. A remote, unauthenticated attacker could send a forged assertion signed with an untrusted certificate while legitimate requests were being processed, and it could be accepted as trusted without ever reaching the STS. Only services that use STSTokenValidator to validate SAML tokens without alwaysValidateToSts set are affected.  Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://lists.apache.org/thread.html/ssdr417qgms9fjl0m8802xd8170wnk1l vendor-advisoryIssue TrackingVendor Advisory
• http://www.openwall.com/lists/oss-security/2026/10/09/10 Mailing ListThird Party Advisory