CVE-2026-65600: Traefik before v2.11.52 Authentication Bypass via ReplacePathRegex
- Is it exploited?
Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of .
VulnCheck KEV lists it since . VulnCheck's own honeypots also recorded exploitation attempts.
- How likely is exploitation in the next 30 days?
- 0.6%
EPSS score, percentile 49.7 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 7.8 High
CVSS v4.0 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- before 2.11.52
- from 3.6.0 to before 3.6.23
- from 3.7.0 to before 3.7.7
Unaffected 2.11.52; 3.6.23; 3.7.7
Source: CISA KEV 2026.10.29, as of ; VulnCheck KEV, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
Description
Traefik before v2.11.52 Authentication Bypass via ReplacePathRegex
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.
Source: CVE List, as of . About the data.
What to do
Advisories and patches
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
Versions by product, as listed in the CVE record (3 products)
| Status | Versions |
|---|---|
| Affected | before 2.11.52 |
| Unaffected | 2.11.52 |
Versions not listed are: unaffected.
| Status | Versions |
|---|---|
| Affected | from 3.6.0 to before 3.6.23 |
| Unaffected | 3.6.23 |
Versions not listed are: unaffected.
| Status | Versions |
|---|---|
| Affected | from 3.7.0 to before 3.7.7 |
| Unaffected | 3.7.7 |
Versions not listed are: unaffected.
Versions the record lists as unaffected: 2.11.52, 3.6.23, 3.7.7.
Source: CVE List, as of . About the data.
Weakness
CWE-22
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |