CVE-2026-32305
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-287 · Improper authentication
- Record status
- Modified
Affected
- Traefik < 2.11.41
- Traefik ≤ 3.6.11
- Traefik 3.7.0
Attack profile CVSS 4.0 · 7.8
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- None
- Privileges needed
- None
- User interaction
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-32305.md and follow it. Check whether this project is affected by CVE-2026-32305. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/traefik/traefik/releases/tag/v2.11.41
- https://github.com/traefik/traefik/releases/tag/v3.6.11
- https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.2
- https://github.com/traefik/traefik/security/advisories/GHSA-wvvq-wgcr-9q48
References
- https://github.com/traefik/traefik/releases/tag/v2.11.41
- https://github.com/traefik/traefik/releases/tag/v3.6.11
- https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.2
- https://github.com/traefik/traefik/security/advisories/GHSA-wvvq-wgcr-9q48
- 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