Bug 2558490 (CVE-2026-111814)

Summary: CVE-2026-111814 trafficserver: Apache Traffic Server: Default server_session_sharing.match omits MASK_CERT, allowing pooled mTLS identity confusion at the origin
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Apache Traffic Server. Its default outbound session-sharing policy can reuse an existing Transport Layer Security (TLS) connection authenticated with one client certificate for a transaction configured to present a different certificate. A remote attacker could exploit this flaw to bypass mutual TLS authentication without valid credentials, potentially gaining unauthorized access across tenant boundaries.
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Description OSIDB Bzimport 2026-10-21 19:21:51 UTC 
Apache Traffic Server's default outbound session-sharing policy can reuse a pooled TLS session authenticated with one client certificate for a transaction configured to present a different one.



This issue affects Apache Traffic Server: from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.



Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.