9.1

CVE-2026-85597: Traefik before v2.11.55 and v3.0.0 through v3.7.10 mTLS Bypass via TLS Option Conflict

Analyzed
AliasesCGA-7xq9-cf6g-grv5CGA-wrfh-pf67-5f9q
Published 04-09-2026Last modified 08-10-2026

Vulnerability summary

CVE-2026-85597 is a critical (CVSS 9.1) Incorrect Authorization vulnerability in traefik. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 28.8% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Prioritisepublic exploit

Public exploit (GitHub, Date unknown)

Source freshness unavailable

How is this decided?
CVSS score
9.1/10
010
Critical · v3.1 (NVD)
EPSS score
0.35%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1github

Timeline

  1. 04-09-2026
    PublishedVulnerability first disclosed.
  2. 08-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.35%

Chance of exploitation in the next 30 days

Percentile

29%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.35% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • githubUnverified

    Traefik

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard1 product
  • traefik-3.6All versions (No fix recorded)
Traefik1 product
  • traefik≥ 3.0.0, ≤ 3.7.10 | < 2.11.55 | ≥ 3.0.0, < 3.7.11
Wolfi1 product
  • traefik-3.6All versions (No fix recorded)

3 vendors · 3 products

References

4 links