CVE-2026-88007: traefik traefik

CVSS 9.1 (critical) · published 2026-09-10

Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.0 until 2.11.57 and 3.7.13, the HTTP/3 entrypoint ConnContext does not call service.AddTransportOnContext, so kerberosRoundTripper uses a shared backend transport instead of a transport dedicated to each frontend connection. With HTTP/3 enabled, a backend using connection-bound NTLM or Negotiate authentication, and backend keep-alive, an unrelated client can reuse a backend connection authenticated for a victim, read victim-only data, and act as that victim without the victim credentials. This issue is fixed in 2.11.57 and 3.7.13.

Affected products (NVD): traefik traefik

Fixed in (NVD): 2.11.56, 3.7.12

Weakness: CWE-287, CWE-863

Source: NVD CVE-2026-88007

References

• https://github.com/traefik/traefik/commit/ff39c47d7459dec9cd8de63c1a4e7aa7315bdc1c
• https://github.com/traefik/traefik/pull/13812
• https://github.com/traefik/traefik/releases/tag/v2.11.57
• https://github.com/traefik/traefik/releases/tag/v3.7.13
• https://github.com/traefik/traefik/security/advisories/GHSA-qqjf-53cj-pwvv

Check your software

Connect an AI agent to the FixLane MCP server or ask the Telegram bot to check what you have installed against incidents with a verified fixed version.