Bug 2571847 (CVE-2026-123872)

Summary: CVE-2026-123872 nodejs: Node.js: Client certificate authentication bypass via TLS renegotiation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Node.js. An authenticated remote attacker can bypass client certificate authentication policies on servers configuring different security requirements per hostname. By renegotiating an established Transport Layer Security (TLS) connection and changing the target server name, the attacker can carry forward their existing authenticated session to gain unauthorized access to restricted endpoints.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-11-11 18:41:12 UTC 
A client certificate authentication bypass in Node.js TLS lets a client change the servername during TLS 1.2 renegotiation to reach endpoints it was not authorized for. On a server that applies different client-certificate policies per hostname, for example stricter admin-only client-cert auth on one host and ordinary client-cert auth on another, a client that authenticates for a permitted host can renegotiate the TLS 1.2 connection under a different servername and carry its existing authentication to the protected host, bypassing the stricter policy. This vulnerability affects Node.js 26.x, 24.x, and 22.x.