Authentication bypass via shared SAML trust state
Published Oct 9, 2026 · Updated Oct 9, 2026
Authentication bypass in Apache CXF STSTokenValidator allows remote attackers to submit forged SAML assertions during concurrent requests. The validator stores its certificate-trust result in an object shared across requests, allowing an assertion signed with an untrusted certificate to inherit another request's trusted result and bypass STS validation. Exploitation requires concurrent legitimate requests and a service using STSTokenValidator for SAML tokens without alwaysValidateToSts enabled; the consequence is acceptance of an untrusted assertion.
Summary
What happened
Authentication bypass in Apache CXF STSTokenValidator allows remote attackers to submit forged SAML assertions during concurrent requests. The validator stores its certificate-trust result in an object shared across requests, allowing an assertion signed with an untrusted certificate to inherit another request's trusted result and bypass STS validation. Exploitation requires concurrent legitimate requests and a service using STSTokenValidator for SAML tokens without alwaysValidateToSts enabled; the consequence is acceptance of an untrusted assertion.
The record
- CVE
- CVE-2026-97791
- Published
- Oct 9, 2026
- Updated
- Oct 9, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache CXF
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 9, 2026CVE publishedPublication date reported by the CVE source.
- Oct 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <3.6.13
- Affected versionversion=4.0.0 <4.1.9
- Affected versionversion=4.2.0 <4.2.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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