CVE-2026-65601

MEDIUM

Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef

Title source: cna
STIX 2.1

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.

References (3)

Core 3
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-qq9q-x9w4-chhj)
https://github.com/traefik/traefik/security/advisories/GHSA-qq9q-x9w4-chhj
Third Party Advisory third-party-advisory
VulnCheck Advisory: Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef
https://www.vulncheck.com/advisories/traefik-before-namespace-confusion-via-httproute-extensionref

Scores

CVSS v4 5.3
EPSS 0.0024
EPSS Percentile 15.0%
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-863
Status published
Products (2)
traefik/traefik 3.7.0 - 3.7.7
traefik/traefik 3.7.7
Published Jul 22, 2026
Tracked Since Jul 22, 2026