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TI-2026-24834 Aliases CVE-2026-32305GHSA-wvvq-wgcr-9q48

Traefik mTLS bypass via fragmented ClientHello SNI extraction failure

Priority MEDIUM 40CWE-1188Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · None · None
Fix status
Partial Red Hat: 2 fixed, 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-287.

Summary

Traefik is an HTTP reverse proxy and load balancer. Versions 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 are vulnerable to mTLS bypass through the TLS SNI pre-sniffing logic related to fragmented ClientHello packets. When a TLS ClientHello is fragmented across multiple records, Traefik's SNI extraction may fail with an EOF and return an empty SNI. The TCP router then falls back to the default TLS configuration, which does not require client certificates by default. This allows an attacker to bypass route-level mTLS enforcement and access services that should require mutual TLS authentication. This issue is patched in versions 2.11.41, 3.6.11 and 3.7.0-ea.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0042 36th percentileScored 2026-11-07
Fix Partial traefik (traefik): 2.11.41, 3.6.11, 3.7.0-ea.2github.com/traefik/traefik/v3 (Go): 3.7.0-ea.2, 3.6.11+1 more productRed Hat: 2 advisoriesRed Hat: 2 fixed, 1 without a fix

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 2.11.41; 3.0.0-beta1 to before 3.6.11; 3.7.0-ea.1 to before 3.7.0-ea.22.11.41, 3.6.11, 3.7.0-ea.2Patch availableCNA
—github.com/traefik/traefik/v3 (Go)3.7.0-ea.1 to before 3.7.0-ea.23.7.0-ea.2Patch availableGHSA-wvvq-wgcr-9q48
—github.com/traefik/traefik/v3 (Go)before 3.6.113.6.11Patch availableGHSA-wvvq-wgcr-9q48
—github.com/traefik/traefik/v2 (Go)before 2.11.412.11.41Patch availableGHSA-wvvq-wgcr-9q48
—github.com/traefik/traefik (Go)up to 1.7.34—No fix listedGHSA-wvvq-wgcr-9q48
  • traefik Vendortraefik Affected before 2.11.41; 3.0.0-beta1 to before 3.6.11; 3.7.0-ea.1 to before 3.7.0-ea.2 Fixed in 2.11.41, 3.6.11, 3.7.0-ea.2 Patch available CNA
  • github.com/traefik/traefik/v3 (Go) Vendor— Affected 3.7.0-ea.1 to before 3.7.0-ea.2 Fixed in 3.7.0-ea.2 Patch available GHSA-wvvq-wgcr-9q48
  • github.com/traefik/traefik/v3 (Go) Vendor— Affected before 3.6.11 Fixed in 3.6.11 Patch available GHSA-wvvq-wgcr-9q48
  • github.com/traefik/traefik/v2 (Go) Vendor— Affected before 2.11.41 Fixed in 2.11.41 Patch available GHSA-wvvq-wgcr-9q48
  • github.com/traefik/traefik (Go) Vendor— Affected up to 1.7.34 Fixed in — No fix listed GHSA-wvvq-wgcr-9q48

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*before 2.11.41; 3.0.0 – 3.6.11Vulnerabletraefik
cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:*3.7.0 ea1Vulnerabletraefik
  • cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* Versions before 2.11.41; 3.0.0 – 3.6.11 Vulnerable ·traefik
  • cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:* Versions 3.7.0 ea1 Vulnerable ·traefik

Remediation

  • Fix · CNA traefik (traefik) Fixed in 2.11.41, 3.6.11, 3.7.0-ea.2
  • Fix · GHSA-wvvq-wgcr-9q48 github.com/traefik/traefik/v3 (Go) Fixed in 3.7.0-ea.2 Advisory →
  • Fix · GHSA-wvvq-wgcr-9q48 github.com/traefik/traefik/v3 (Go) Fixed in 3.6.11 Advisory →
  • Fix · GHSA-wvvq-wgcr-9q48 github.com/traefik/traefik/v2 (Go) Fixed in 2.11.41 Advisory →

Red Hat 2 advisories

  • 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
  • RHSA-2026:10175 Released 2026-04-23 · Red Hat rating Important
    Red Hat OpenShift Dev Spaces 3.27.1 Release.
    • Red Hat OpenShift Dev Spaces 3.27 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/devspaces-rhel9-operator +8

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat OpenShift GitOpsAffectedNo fix planned: Will not fix
Red Hat OpenShift Dev Spaces 3.27Fixed RHSA-2026:10175
Red Hat OpenShift Dev Spaces 3.28Fixed RHSA-2026:21772
Not affected: 2 products
  • Red Hat OpenShift Dev Spaces 3.27
  • Red Hat OpenShift Dev Spaces 3.28

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-32305
  2. 2026-10-03 Alias added: GHSA-wvvq-wgcr-9q48

References

Patch 1

Advisory 1

Other 4

  • 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