What’s Vulnerable › Vulnerabilities

CVE-2026-65601: Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-22 · updated 2026-10-08
• Weakness: CWE-863

Description

Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route author holding a ReferenceGrant for a cross-namespace Service could therefore bind a Traefik Middleware from the backend namespace without a separate grant for that middleware, potentially injecting trusted reverse-proxy identity headers into downstream requests. The issue is fixed in version 3.7.7.

Affected products

• Traefik: from 3.7.0 before 3.7.7 — fixed in 3.7.7

How to fix

Upgrade to a fixed version: Traefik 3.7.7. Check the vendor advisory for mitigations.

References

• https://github.com/traefik/traefik/commit/26c96a3935cafb473f4a5bae1886560d9aa4e4f0
• https://github.com/traefik/traefik/security/advisories/GHSA-qq9q-x9w4-chhj
• https://www.vulncheck.com/advisories/traefik-before-namespace-confusion-via-httproute-extensionref

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