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CVE-2026-85597

9.1, critical

traefik Incorrect Authorization Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
9.1, critical critical CVSS v3.1
EPSS, next 30 days
0.4% higher than 27.2% of scored CVEs
Exploitation
Exploit code published
Published
4 Sept 2026a month ago

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.

Details

Vendor
Traefik
Product
traefik
Weakness
CWE-863 (opens in a new tab)
Status
Analyzed
Updated
8 Oct 2026
Assigner
disclosure@vulncheck.com

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References 2

Exploit code 1

Advisories 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Traefik CVEs

Every Traefik CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-88007 traefik Improper Authentication Vulnerability EPSS 0.6% 9.1, critical
  • CVE-2026-88008 traefik HTTP Request Smuggling Vulnerability EPSS 0.5% 9.1, critical
  • CVE-2026-88879 Traefik is an HTTP reverse proxy and load balancer EPSS 0.3% 8.2, high
  • CVE-2026-88004 Traefik is an open source HTTP reverse proxy and load balancer EPSS 0.5% 7.4, high
  • CVE-2026-88009 traefik HTTP Request Smuggling Vulnerability EPSS 0.4% 8.2, high
  • CVE-2026-88011 Traefik is an open source HTTP reverse proxy and load balancer EPSS 0.4% 8.1, high
  • CVE-2026-85594 traefik Authorization Bypass Through User-Controlled Key Vulnerability EPSS 0.5% 9.8, critical
  • CVE-2026-85595 traefik Improper Authentication Vulnerability EPSS 0.7% 9.8, critical

Beyond this page

Is CVE-2026-85597 in your network?

This page tells you how dangerous CVE-2026-85597 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

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    Find it before attackers do

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  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.