CVE-2026-119574

Summary

Traefik from 3.2.0 before 3.7.15 contains a data race in the experimental FastProxy that allows unauthenticated attackers to crash the process by abusing HTTP/1 protocol upgrades. Attackers can repeatedly open and abort upgraded connections such as WebSocket, corrupting the unsynchronized shared bufio.Reader and triggering an unrecovered panic that terminates Traefik.

Impact & exploitability

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://github.com/traefik/traefik/security/advisories/GHSA-ww7c-q3mv-xx22 ↗

Additional information

• NVD record
• https://github.com/traefik/traefik/security/advisories/GHSA-ww7c-q3mv-xx22Patch
• https://www.vulncheck.com/advisories/traefik-3.2.0-before-3.7.15-fastproxy-data-race-denial-of-serviceAdvisory