CVE-2026-65600
Traefik versions <= v2.11.51, >= v3.6.0 <= v3.6.22, and >= v3.7.0 <= v3.7.6 contain an authentication bypass via path traversal in the ReplacePathRegex middleware. When ReplacePathRegex is configured with a regex that captures user-controlled path segments without a mandatory path separator (e.g. regex "^/api(.*)", replacement "/$1"), the middleware forwards the replaced path to the backend without validating that it matches its normalized form. An unauthenticated remote attacker can send a crafted request (e.g. GET /api../admin) that produces an un-normalized path such as /../admin, which a backend that normalizes paths resolves to a protected route, bypassing authentication middleware. Fixed in v2.11.52, v3.6.23, and v3.7.7.
- CVSS 4.0
- 7.8
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N - CVSS 3.1
- 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-25)
- CWE
- CWE-22
- Published
- Modified
- Record from
- the NVD, synced
Affected
- traefik:traefik
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-cxjq-mrr5-89rv | Go | github.com/traefik/traefik/v2 | <2.11.52 | 2.11.52 |
| GHSA-cxjq-mrr5-89rv | Go | github.com/traefik/traefik/v3 | <3.6.23 | 3.6.23 |
| GHSA-cxjq-mrr5-89rv | Go | github.com/traefik/traefik/v3 | >=3.7.0 <3.7.7 | 3.7.7 |
| GHSA-cxjq-mrr5-89rv | Go | github.com/traefik/traefik | <=1.7.34 | no fix published |
| GO-2026-6208 | Go | github.com/traefik/traefik | all versions | no fix published |
| GO-2026-6208 | Go | github.com/traefik/traefik/v2 | <2.11.52 | 2.11.52 |
| GO-2026-6208 | Go | github.com/traefik/traefik/v3 | <3.6.23 >=3.7.0 <3.7.7 | 3.6.23, 3.7.7 |