CVE-2026-88008
Fixed in a distro release EPSS <1%CVSS 7.0
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.
Products: traefik
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Go | github.com/traefik/traefik | no fix |
| Go | github.com/traefik/traefik/v2 | 2.11.57 |
| Go | github.com/traefik/traefik/v3 | 3.7.13 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | traefik-3.6 | no fix |
| Chainguard | traefik-fips-3.6 | no fix |
| SUSE Linux Enterprise Server 16.0 | govulncheck-vulndb | 0.0.20260916T180043-160000.1.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | govulncheck-vulndb | 0.0.20260916T180043-160000.1.1 |
| Wolfi | traefik-3.6 | no fix |
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260916T180043-160000.1.1 |
| openSUSE Tumbleweed | traefik | 3.7.13-1.1 |