CVE-2026-52844

Caddy: Windows `file_server` path authorization bypass via encoded backslash

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, on Windows, Caddy path matchers treat /private\secret.txt as outside /private/*, but file_server later resolves the same request path as private\secret.txt on disk. An unauthenticated remote client can bypass Caddy path-scoped auth/deny routes protecting /private/*. This vulnerability is fixed in 2.11.4.

Affected

caddyserver · caddy

CVSS v3.1 GITHUB

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

0.62% chance of exploitation in the next 30 days, 49th percentile

Published

2026-06-23

Proof-of-concept exploits (1)

• advisories/GHSA-qrp7-cvwr-j2c6

Security advisories

• caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6

References

• CVE Record
• NVD entry