V3: Traefik: TCP readTimeout bypass via STARTTLS on Postgres (CVE-2026-25949)
A vulnerability in Traefik prior to version 3.6.8 allows an unauthenticated remote client to bypass the readTimeout setting on TCP entrypoints by sending a Postgres SSLRequest (STARTTLS) prelude and then stalling. This causes connections to remain open indefinitely, leading to resource exhaustion and denial of service.
AI Analysis
Technical Summary
Traefik versions before 3.6.8 contain a vulnerability where an unauthenticated client can send the 8-byte Postgres SSLRequest (STARTTLS) prelude to bypass the configured readTimeout on TCP entrypoints. This occurs during protocol detection before routing, allowing the client to stall the connection indefinitely. The result is exhaustion of file descriptors and goroutines, causing a denial of service condition. The issue is tracked as CVE-2026-25949 and is addressed in Traefik version 3.6.8.
Potential Impact
An unauthenticated attacker can cause Traefik to keep TCP connections open indefinitely by exploiting the STARTTLS handling for Postgres SSLRequest. This leads to exhaustion of system resources such as file descriptors and goroutines, resulting in denial of service for legitimate users. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
An official fix is available in Traefik version 3.6.8. Users should upgrade to version 3.6.8 or later to remediate this vulnerability. No other mitigations are specified or required according to the vendor advisory.
V3: Traefik: TCP readTimeout bypass via STARTTLS on Postgres (CVE-2026-25949)
Description
A vulnerability in Traefik prior to version 3.6.8 allows an unauthenticated remote client to bypass the readTimeout setting on TCP entrypoints by sending a Postgres SSLRequest (STARTTLS) prelude and then stalling. This causes connections to remain open indefinitely, leading to resource exhaustion and denial of service.
CVSS v3.1
Score 7.5high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Traefik versions before 3.6.8 contain a vulnerability where an unauthenticated client can send the 8-byte Postgres SSLRequest (STARTTLS) prelude to bypass the configured readTimeout on TCP entrypoints. This occurs during protocol detection before routing, allowing the client to stall the connection indefinitely. The result is exhaustion of file descriptors and goroutines, causing a denial of service condition. The issue is tracked as CVE-2026-25949 and is addressed in Traefik version 3.6.8.
Potential Impact
An unauthenticated attacker can cause Traefik to keep TCP connections open indefinitely by exploiting the STARTTLS handling for Postgres SSLRequest. This leads to exhaustion of system resources such as file descriptors and goroutines, resulting in denial of service for legitimate users. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
An official fix is available in Traefik version 3.6.8. Users should upgrade to version 3.6.8 or later to remediate this vulnerability. No other mitigations are specified or required according to the vendor advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-89p3-4642-cr2w
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-25949"]
- Ecosystems
- ["Go"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a50ba6d68715ace4357fb32
Added to database: 07/10/2026, 09:25:01 UTC
Last enriched: 07/10/2026, 09:51:04 UTC
Last updated: 09/10/2026, 19:36:53 UTC
Views: 32
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