CVE-2026-85597
Traefik before v2.11.55 and v3.0.0 through v3.7.10 mTLS Bypass via TLS Option Conflict
- State
- Published
- Severity
- 8.2 High
- Published
- Sep 4, 2026
- Updated
- Oct 8, 2026
- Reserved
- Sep 4, 2026
Description
Traefik before v2.11.55 and v3.0.0 through v3.7.10 contain a TLS option conflict resolution vulnerability that allows unauthenticated attackers to bypass client-certificate authentication by creating conflicting TLS options on multi-host routers. Attackers can reach protected backends by exploiting shared TLS resolution across multiple hostnames in a single router rule, causing the strict mTLS requirement to fall back to default options for all hosts.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.2 High | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N | VulnCheck |
Weaknesses
- CWE-863 Incorrect Authorization
Affected Products
| Product | Versions |
|---|---|
traefiktraefik |
|
traefiktraefik |
|
References
- GitHub Security Advisory (GHSA-g55h-rg46-x9c5)vendor-advisory
- VulnCheck Advisory: Traefik before v2.11.55 mTLS Bypass via TLS Option Conflictthird-party-advisory
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