CVE-2026-52844

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

State: Published
Severity: 7.5 High
Published: Jun 23, 2026
Updated: Jun 23, 2026
Reserved: Jun 8, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N	GitHub_M

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-284 Improper Access Control

Affected Products

Product	Versions
caddycaddyserver	< 2.11.4Affected

References

https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6

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