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TI-2026-29568 Aliases CVE-2026-40912GHSA-6jwx-7vp4-9847

Traefik: StripPrefixRegex auth bypass via Path/RawPath desync

Priority MEDIUM 41CWE-706Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

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 high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment path in X-Forwarded-Uri, which does not match the protected path patterns and therefore allows the request through. The backend then normalizes the dot-segment to the real path per RFC 3986 and serves the protected content An unauthenticated attacker can exploit this against any backend that performs dot-segment normalization. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00767 55th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed traefik (traefik): 2.11.43, 3.6.14, 3.7.0-rc.2github.com/traefik/traefik/v3 (Go): 3.7.0-rc.2, 3.6.14+1 more productRed Hat: 1 advisory

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
traefiktraefikbefore 2.11.43; 3.0.0-beta1 to before 3.6.14; 3.7.0-ea.1 to before 3.7.0-rc.22.11.43, 3.6.14, 3.7.0-rc.2Patch availableCNA
—github.com/traefik/traefik/v3 (Go)3.7.0-ea.1 to before 3.7.0-rc.23.7.0-rc.2Patch availableGHSA-6jwx-7vp4-9847
—github.com/traefik/traefik/v3 (Go)3.0.0-beta1 to before 3.6.143.6.14Patch availableGHSA-6jwx-7vp4-9847
—github.com/traefik/traefik/v2 (Go)before 2.11.432.11.43Patch availableGHSA-6jwx-7vp4-9847
—github.com/traefik/traefik (Go)up to 1.7.34—No fix listedGHSA-6jwx-7vp4-9847
  • traefik Vendortraefik Affected before 2.11.43; 3.0.0-beta1 to before 3.6.14; 3.7.0-ea.1 to before 3.7.0-rc.2 Fixed in 2.11.43, 3.6.14, 3.7.0-rc.2 Patch available CNA
  • github.com/traefik/traefik/v3 (Go) Vendor— Affected 3.7.0-ea.1 to before 3.7.0-rc.2 Fixed in 3.7.0-rc.2 Patch available GHSA-6jwx-7vp4-9847
  • github.com/traefik/traefik/v3 (Go) Vendor— Affected 3.0.0-beta1 to before 3.6.14 Fixed in 3.6.14 Patch available GHSA-6jwx-7vp4-9847
  • github.com/traefik/traefik/v2 (Go) Vendor— Affected before 2.11.43 Fixed in 2.11.43 Patch available GHSA-6jwx-7vp4-9847
  • github.com/traefik/traefik (Go) Vendor— Affected up to 1.7.34 Fixed in — No fix listed GHSA-6jwx-7vp4-9847

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*before 2.11.43; 3.0.0 to before 3.6.14Vulnerabletraefik
cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:*3.7.0 ea1Vulnerabletraefik
cpe:2.3:a:traefik:traefik:3.7.0:ea2:*:*:*:*:*:*3.7.0 ea2Vulnerabletraefik
cpe:2.3:a:traefik:traefik:3.7.0:ea3:*:*:*:*:*:*3.7.0 ea3Vulnerabletraefik
cpe:2.3:a:traefik:traefik:3.7.0:rc1:*:*:*:*:*:*3.7.0 rc1Vulnerabletraefik
  • cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* Versions before 2.11.43; 3.0.0 to before 3.6.14 Vulnerable ·traefik
  • cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:* Versions 3.7.0 ea1 Vulnerable ·traefik
  • cpe:2.3:a:traefik:traefik:3.7.0:ea2:*:*:*:*:*:* Versions 3.7.0 ea2 Vulnerable ·traefik
  • cpe:2.3:a:traefik:traefik:3.7.0:ea3:*:*:*:*:*:* Versions 3.7.0 ea3 Vulnerable ·traefik
  • cpe:2.3:a:traefik:traefik:3.7.0:rc1:*:*:*:*:*:* Versions 3.7.0 rc1 Vulnerable ·traefik

Remediation

  • Fix · CNA traefik (traefik) Fixed in 2.11.43, 3.6.14, 3.7.0-rc.2
  • Fix · GHSA-6jwx-7vp4-9847 github.com/traefik/traefik/v3 (Go) Fixed in 3.7.0-rc.2 Advisory →
  • Fix · GHSA-6jwx-7vp4-9847 github.com/traefik/traefik/v3 (Go) Fixed in 3.6.14 Advisory →
  • Fix · GHSA-6jwx-7vp4-9847 github.com/traefik/traefik/v2 (Go) Fixed in 2.11.43 Advisory →

Red Hat 1 advisory

  • RHSA-2026:21772 Released 2026-05-28 · Red Hat rating Important
    Red Hat OpenShift Dev Spaces 3.28.0 Release.
    • Red Hat OpenShift Dev Spaces 3.28 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/openvsx-rhel9 +3

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift Dev Spaces 3.28Fixed RHSA-2026:21772
Not affected: 1 product
  • Red Hat OpenShift Dev Spaces 3.28

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-40912
  2. 2026-10-03 Alias added: GHSA-6jwx-7vp4-9847

References

Exploit 1

Advisory 1

Other 8

  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2023-25774 Uncontrolled Resource Consumption in Traefik CVSS 3.1HIGH 7.5
  • TI-2025-40914 Traefik doesn't Prevent Path Normalization Bypass in Router + Middleware Rules CVSS 4.0MEDIUM 6.9
  • TI-2022-07529 Authorization header displayed in the debug logs CVSS 3.1MEDIUM 6.5
  • TI-2024-30459 HTTP client can remove the X-Forwarded headers in Traefik CVSS 3.1CRITICAL 9.8
  • TI-2026-60261 Traefik v3.7.0 Authentication Bypass via from-to-www-redirect CVSS 4.0CRITICAL 9.3
See all 83 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences