Vulnerability · Published Jul 22, 2026 · Assigned by VulnCheck
CVE-2026-65602Traefik before 3.6.23 IngressRouteTCP ServersTransport Namespace Bypass
Medium 5.3
In plain English
A medium-severity incorrect authorization in traefik from traefik. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Traefik 3.6.0 through 3.6.22 and 3.7.0 through 3.7.6 fail to enforce the crossProviderNamespaces allowlist for IngressRouteTCP service serversTransport references (the allowlist was only enforced for HTTP serversTransport references). A low-privileged Kubernetes user in a namespace not listed in crossProviderNamespaces can set serversTransport: foo@file on an IngressRouteTCP service, causing Traefik to accept the forbidden cross-provider reference and use a file-provider TCPServersTransport — including privileged backend mTLS client certificates, SPIFFE identity, or PROXY-protocol settings. This is fixed in 3.6.23 and 3.7.7.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/traefik/traefik | no fix listed | GO-2026-6192 |
| Go | github.com/traefik/traefik/v2 | no fix listed | GO-2026-6192 |
| Go | github.com/traefik/traefik/v3 | 3.6.23 | GHSA-42cj-m3vj-89wv |
| Go | github.com/traefik/traefik/v3 | 3.7.7 | GHSA-42cj-m3vj-89wv |
| Go | github.com/traefik/traefik/v3 | 3.6.23, 3.7.7 | GO-2026-6192 |
Affected products (as reported)
Weakness: CWE-863 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
References
- GitHub Security Advisory (GHSA-42cj-m3vj-89wv) vendor-advisory
- Patch Commit patch
- VulnCheck Advisory: Traefik before 3.6.23 IngressRouteTCP ServersTransport Namespace Bypass third-party-advisory