Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-85597

CVE-2026-85597HIGH

Traefik before v2.11.55 and v3.0.0 through v3.7.10 mTLS Bypass via TLS Option Conflict

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   P   N   N   H   N   N    8.2   .0035   26.5     —

AFFECTED
  Product  Versions     Fixed
  traefik  unspecified  2.11.55
  traefik  3.0.0 –      —

TIMELINE
  Sep 4   Reserved by VulnCheck
  Sep 4   Published (CNA: VulnCheck)
  Sep 16  EXPLOIT PUBLISHED — CVE-2026-85597 (traefik). Public exploit reference added.

CWE-863 · CNA: VulnCheck · CVSS v4.0 · 2 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
September 4, 2026	Reserved	Reserved by VulnCheck
September 4, 2026	Published	Published (CNA: VulnCheck)
September 16, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-85597 (traefik). Public exploit reference added.

Affected

Affected products and packages — 2 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
traefik	traefik	—	—	2.11.55
traefik	traefik	—	3.0.0	—

Weaknesses

CWE-863

References (2)

https://github.com/traefik/traefik/security/advisories/GHSA-g55h-rg46-x9c5 [Exploit, Mitigation, Patch, Vendor Advisory]
https://www.vulncheck.com/advisories/traefik-before-2.11.55-mtls-bypass-via-tls-option-conflict [Third Party Advisory]

Authoritative record: CVE-2026-85597 at cve.org

Vendors: traefik

Weaknesses: CWE-863

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-85597 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.