Improper Encoding or Escaping of Output in Caddy - CVE-2026-27585
Published: April 27, 2026
Vulnerability identifier: #VU128028
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-27585
CWE-ID: CWE-116
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Caddy
Affected software:
Caddy
Caddy
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass path-related security protections.
The vulnerability exists due to improper sanitization of glob characters in the file matcher when expanding request paths into glob patterns for the try_files directive. A remote attacker can send a specially crafted request path containing backslashes to bypass path-related security protections.
It affects configurations where try_files is used with path-based filtering or upstream access restrictions, and directive ordering can influence whether the protection is bypassed.
How to mitigate CVE-2026-27585
Install security update from vendor's website.