Denial of Service Vulnerability in Traefik HTTP Reverse Proxy and Load Balancer
CVE-2026-25949

7.5HIGH

Key Information:

Vendor

Traefik

Status
Traefik
Vendor
CVE Published:
12 February 2026

What is CVE-2026-25949?

Traefik, an HTTP reverse proxy and load balancer, has a vulnerability that allows unauthenticated clients to exploit the handling of STARTTLS requests. By sending an 8-byte Postgres SSLRequest (STARTTLS) prelude, an attacker can cause connections to remain open indefinitely due to a failure in managing the responding timeouts. This results in a denial of service condition, substantially affecting the availability of services until the vulnerability is addressed. The issue has been resolved in version 3.6.8.

Affected Version(s)

traefik < 3.6.8

References

https://github.com/traefik/traefik/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/traefik/traefik/commit/31e566e9f1d7888...
x_refsource_MISC
https://github.com/traefik/traefik/releases/tag/v3.6.8
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.