CVE-2026-97468: Apache CXF: Authentication bypass via weak cache keys for validated STS tokens

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-09 · updated 2026-10-20
Weakness: CWE-328

Description

Apache CXF's STSTokenValidator and Security Token Service (STS) cached validated security tokens under a non-cryptographic 32-bit hash of the token (Java Arrays.hashCode/hashCode()), and treated a cache hit as proof that the presented token had already been validated. An attacker could craft a token (for example a UsernameToken or a self-signed SAML Assertion) whose hash collides with a cached entry. The token would then be accepted without password validation, signature trust verification or a call to the STS. This could let the attacker authenticate as another user and, through STS token validation or renewal, obtain STS-signed tokens for that identity. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Affected products

Apache Software Foundation Apache CXF: before 3.6.13; from 4.0.0 before 4.1.9; from 4.2.0 before 4.2.4 — fixed in 3.6.13, 4.1.9, 4.2.4

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache CXF 3.6.13, 4.1.9, 4.2.4. Check the vendor advisory for mitigations.

References

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