CVE-2026-41174

MEDIUM EPSS 16.6%
Published Apr 30, 20262mo ago · Modified Jun 17, 20262w ago
4.8 CVSS 4.0
Medium
Find Similar
Published Apr 30, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
4.8
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/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
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
16.6% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 2

CWE-653
CWE-863 Incorrect Authorization Authorization

Affected Products 6

VendorProductVersionRange
traefiktraefik* <2.11.43
traefiktraefik*≥3.0.0  –  <3.6.14
traefiktraefik3.7.0any
traefiktraefik3.7.0any
traefiktraefik3.7.0any
traefiktraefik3.7.0any

References 5

  • github.com https://github.com/traefik/traefik/commit/df00d82fc7f12e07199551832b54de6d0e55414d
    Patch
  • github.com https://github.com/traefik/traefik/releases/tag/v2.11.43
    ProductRelease Notes
  • github.com https://github.com/traefik/traefik/releases/tag/v3.6.14
    ProductRelease Notes
  • github.com https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2
    ProductRelease Notes
  • github.com https://github.com/traefik/traefik/security/advisories/GHSA-xhjw-95fp-8vgq
    ExploitPatchVendor Advisory

Remediation

  • github.com https://github.com/traefik/traefik/commit/df00d82fc7f12e07199551832b54de6d0e55414d
    Patch
  • github.com https://github.com/traefik/traefik/security/advisories/GHSA-xhjw-95fp-8vgq
    ExploitPatchVendor Advisory