CVE-2026-88008

Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.26 until 2.11.57 and 3.7.13, Traefik forwards a client-supplied Connection header requesting Upgrade, the Upgrade: h2c token, and HTTP2-Settings to a shared backend. If the backend accepts h2c and returns 101 Switching Protocols, Traefik enters a raw tunnel and no longer applies routers, BasicAuth, ForwardAuth, IPAllowList, RateLimit, access logging, metrics, or tracing to later HTTP/2 requests, allowing an unauthenticated request through an unprotected route to reach protected paths on the same backend. This issue is fixed in 2.11.57 and 3.7.13.

• CWE-444
• CWE-863

• https://github.com/traefik/traefik/commit/a277e94664ffc1ce9543df552d3bbf48d4d3b8b3Patch
• https://github.com/traefik/traefik/pull/13797Issue Tracking, Patch
• https://github.com/traefik/traefik/releases/tag/v2.11.57Release Notes
• https://github.com/traefik/traefik/releases/tag/v3.7.13Release Notes
• https://github.com/traefik/traefik/security/advisories/GHSA-w4v4-9rw7-5326Patch, Vendor Advisory

Published

Sep 10, 2026

Last Modified

Sep 14, 2026

Status

Analyzed

• Uncovering a hidden BOLA in Appsmith's snapshot logicStrix autonomously discovered a BOLA/IDOR vulnerability in Appsmith's snapshot deletion path.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-88002Open WebUI is an extensible, feature-rich, and user-friendly…6.5
• CVE-2026-88003InvoicePlane is a self-hosted open source application for ma…7.5
• CVE-2026-88004Traefik is an open source HTTP reverse proxy and load balanc…7.4
• CVE-2026-88005Open WebUI is an extensible, feature-rich, and user-friendly…6.5
• CVE-2026-88006Open WebUI is an extensible, feature-rich, and user-friendly…6.5
• CVE-2026-88007Traefik is an open source HTTP reverse proxy and load balanc…9.1
• CVE-2026-88009Traefik is an open source HTTP reverse proxy and load balanc…8.2
• CVE-2026-8801Path equivalence: vulnerability in Progress MOVEit Transfer …9.8
• CVE-2026-88010Traefik is an open source HTTP reverse proxy and load balanc…5.3
• CVE-2026-88011Traefik is an open source HTTP reverse proxy and load balanc…8.1
• CVE-2026-88012Traefik is an open source HTTP reverse proxy and load balanc…5.3
• CVE-2026-88013rclone is a command-line program to sync files and directori…5.3