Bug 2439522 (CVE-2026-25949)

Summary: CVE-2026-25949 github.com/traefik/traefik: Traefik: Denial of Service via stalled STARTTLS requests
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: unspecifiedCC: sdawley
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Traefik, an HTTP reverse proxy and load balancer. An unauthenticated client can exploit this vulnerability by sending a specific 8-byte Postgres SSLRequest (STARTTLS) prelude and then intentionally delaying further communication. This action bypasses Traefik's configured read timeouts, causing connections to remain open indefinitely. The primary consequence is a Denial of Service, as the server's resources become exhausted by these persistent, non-responsive connections.
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Description OSIDB Bzimport 2026-02-12 21:01:37 UTC 
Traefik is an HTTP reverse proxy and load balancer. Prior to 3.6.8, there is a potential vulnerability in Traefik managing STARTTLS requests. An unauthenticated client can bypass Traefik entrypoint respondingTimeouts.readTimeout by sending the 8-byte Postgres SSLRequest (STARTTLS) prelude and then stalling, causing connections to remain open indefinitely, leading to a denial of service. This vulnerability is fixed in 3.6.8.