Auth bypass in Traefik
CVE-2026-85595
Traefik versions before v2.11.55 and versions v3.0.0 through v3.7.10 contain an authentication bypass vulnerability in the digestAuth middleware where unknown usernames receive an empty secret instead of rejection. Attackers can compute a valid digest response using the empty secret and arbitrary credentials to bypass authentication on any digestAuth-protected route without a valid username or password.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (52.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.002
Affected products
Weakness classification (CWE)
References
- github.com/traefik/traefik/security/advisories/GHSA-5w68-77r2-r64c (Exploit, vendor-advisory, Patch, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/traefik-before-2.11.55-authentication-bypass-via-d… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-85595?
- CVE-2026-85595 is a critical-severity vulnerability in Traefik, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-09-04.
- How severe is CVE-2026-85595?
- Critical severity. CVSS v3 base score is 9.8 out of 10.