CVE-2026-41174
Description
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a potential vulnerability in Traefik's Kubernetes CRD provider cross-namespace isolation enforcement. When providers.kubernetesCRD.allowCrossNamespace=false, Traefik correctly rejects direct cross-namespace middleware references from IngressRoute objects, but fails to apply the same restriction to middleware references nested inside a Chain middleware's spec.chain.middlewares[]. An actor with permission to create or update Traefik CRDs in their own namespace can exploit this to cause Traefik to resolve and apply middleware objects from another namespace, bypassing the documented isolation boundary. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
github.com/traefik/traefik/v3Go | >= 3.7.0-ea.1, < 3.7.0-rc.2 | 3.7.0-rc.2 |
github.com/traefik/traefik/v3Go | >= 3.0.0-beta1, < 3.6.14 | 3.6.14 |
github.com/traefik/traefik/v2Go | < 2.11.43 | 2.11.43 |
github.com/traefik/traefikGo | <= 1.7.34 | — |
Affected products
10cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*+ 4 more
- cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*range: <2.11.43
- cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:*
- cpe:2.3:a:traefik:traefik:3.7.0:ea2:*:*:*:*:*:*
- cpe:2.3:a:traefik:traefik:3.7.0:ea3:*:*:*:*:*:*
- cpe:2.3:a:traefik:traefik:3.7.0:rc1:*:*:*:*:*:*
- ghsa-coords5 versionspkg:golang/github.com/traefik/traefikpkg:golang/github.com/traefik/traefik/v2pkg:golang/github.com/traefik/traefik/v3pkg:rpm/opensuse/traefik2&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/traefik&distro=openSUSE%20Tumbleweed
<= 1.7.34+ 4 more
- (no CPE)range: <= 1.7.34
- (no CPE)range: < 2.11.43
- (no CPE)range: >= 3.7.0-ea.1, < 3.7.0-rc.2
- (no CPE)range: < 2.11.44-1.1
- (no CPE)range: < 3.6.15-1.1
Patches
Vulnerability mechanics
References
7- github.com/traefik/traefik/commit/df00d82fc7f12e07199551832b54de6d0e55414dnvdPatchWEB
- github.com/traefik/traefik/security/advisories/GHSA-xhjw-95fp-8vgqnvdExploitPatchVendor AdvisoryWEB
- github.com/advisories/GHSA-xhjw-95fp-8vgqghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-41174ghsaADVISORY
- github.com/traefik/traefik/releases/tag/v2.11.43nvdProductRelease NotesWEB
- github.com/traefik/traefik/releases/tag/v3.6.14nvdProductRelease NotesWEB
- github.com/traefik/traefik/releases/tag/v3.7.0-rc.2nvdProductRelease NotesWEB
News mentions
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