Description
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.
Metrics
CVSS 3.1 5.3/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| traefik | traefik | < 2.11.41; >= 3.0.0-beta1, < 3.6.11; >= 3.7.0-ea.1, < 3.7.0-ea.2 |
| Red Hat | Red Hat OpenShift Dev Spaces 3.27 | — |
| Red Hat | Red Hat OpenShift Dev Spaces 3.28 | — |
| Red Hat | Red Hat OpenShift GitOps | — |
References
- https://github.com/traefik/traefik/releases/tag/v2.11.41Release Notes
- https://github.com/traefik/traefik/releases/tag/v3.6.11Release Notes
- https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.2Release Notes
- https://github.com/traefik/traefik/security/advisories/GHSA-wvvq-wgcr-9q48Patch, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:10175
- https://access.redhat.com/errata/RHSA-2026:21772
- https://access.redhat.com/security/cve/CVE-2026-32305
- https://bugzilla.redhat.com/show_bug.cgi?id=2449595
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32305.json
Timeline
- Published
- Mar 20, 2026
- Last modified
- Jul 15, 2026
- NVD status
- Modified