Vulnerability in Traefik
CVE-2026-88010
Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.7.13, checkPassword in pkg/middlewares/auth/basic_auth.go constructs the BasicAuth singleflight key from the submitted password and stored secret. Concurrent requests for absent usernames therefore coalesce on one key while configured usernames perform separate password hashes, creating an unauthenticated timing discrepancy that reveals whether a username exists. Sequential checks remain cost-equalized, Traefik v2 and Digest authentication are not affected, and the issue does not disclose credentials or bypass authentication. This issue is fixed in version 3.7.13.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (23.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 23.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.003 · change: -0.004
Affected products
- Traefik — versions >= 3.6.11, < 3.7.13
Weakness classification (CWE)
References
- github.com/traefik/traefik/security/advisories/GHSA-8fcf-v89g-xpg6 (Patch, Vendor Advisory)
- github.com/traefik/traefik/pull/13816 (Patch, Issue Tracking)
- github.com/traefik/traefik/commit/ddc1bf4660b85fd61fafdd821eb8216fb1a0b130 (Patch)
- github.com/traefik/traefik/releases/tag/v3.7.13 (Release Notes)
Frequently asked questions
- What is CVE-2026-88010?
- CVE-2026-88010 is a medium-severity vulnerability in Traefik, classified under CWE-208. CVSS score: 5.3/10. Published 2026-09-22.
- How severe is CVE-2026-88010?
- Medium severity. CVSS v3 base score is 5.3 out of 10.