CVSS 4.0
2.1 lowCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NCVE-2026-71326
Low (2.1) in traefik traefik. EPSS 0.3% chance of exploitation in the next 30 days. Fixed in github.com/traefik/traefik/v3 3.6.25, 3.7.10.
Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.6.25 and 3.7.10, Traefik's BasicAuth middleware in pkg/middlewares/auth/basic_auth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and secret, allowing an attacker who has a valid credential and the stored hash to authenticate as an unconfigured username when headerField trusts the forwarded identity. This issue is fixed in 3.6.25 and 3.7.10.
Severity
CVSS 3.1
3.8 lowCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 27% of CVEs (scores of 2026-11-01)
- CWE
- CWE-287
- Published
- Modified
- Record from
- the NVD, synced
Affected
- traefik:traefik
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-6765-c87h-8mrf | Go | github.com/traefik/traefik/v3 | >=3.6.11 <3.6.25 | 3.6.25 |
| GHSA-6765-c87h-8mrf | Go | github.com/traefik/traefik/v3 | >=3.7.0 <3.7.10 | 3.7.10 |
| GO-2026-6204 | Go | github.com/traefik/traefik | all versions | no fix published |
| GO-2026-6204 | Go | github.com/traefik/traefik/v2 | all versions | no fix published |
| GO-2026-6204 | Go | github.com/traefik/traefik/v3 | >=3.6.11 <3.6.25 >=3.7.0 <3.7.10 | 3.6.25, 3.7.10 |
References
- https://github.com/traefik/traefik/commit/b5ace8eb5d6779980567f5e75efd2d9e08b7e350
- https://github.com/traefik/traefik/pull/13572
- https://github.com/traefik/traefik/releases/tag/v3.6.25
- https://github.com/traefik/traefik/releases/tag/v3.7.10
- https://github.com/traefik/traefik/security/advisories/GHSA-6765-c87h-8mrf