Traefik is an open-source edge router that makes publishing services a fun and easy experience. Prior to 2.11.54, 3.6.25, and 3.7.10, cross-namespace @kubernetescrd references are not rejected for TraefikService backend references resolved by the service resolver. A tenant confined by RBAC to a single namespace can therefore bind its own router to a TraefikService owned by another namespace and expose or reroute that namespace's backend, defeating the namespace isolation allowCrossNamespace=false is meant to enforce. This issue is fixed in version 2.11.54, 3.6.25, 3.7.10.
https://github.com/traefik/traefik/security/advisories/GHSA-62fc-8686-hfmq
https://github.com/traefik/traefik/releases/tag/v3.7.10
https://github.com/traefik/traefik/releases/tag/v3.6.25
https://github.com/traefik/traefik/releases/tag/v2.11.54
https://github.com/traefik/traefik/commit/65ebf4b47fbdc33e3856803a5844a404e094d52d
Published: 2026-08-06
Updated: 2026-08-06
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 9.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Severity: Critical
Base Score: 4.8
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
Severity: Medium
EPSS: 0.00132