CVE-2026-30852

Caddy is an extensible server platform that uses TLS by default. From version 2.7.5 to before version 2.11.2, the vars_regexp matcher in vars.go:337 double-expands user-controlled input through the Caddy replacer. When vars_regexp matches against a placeholder like {http.request.header.X-Input}, the header value gets resolved once (expected), then passed through repl.ReplaceAll() again (the bug). This means an attacker can put {env.DATABASE_URL} or {file./etc/passwd} in a request header and the server will evaluate it, leaking environment variables, file contents, and system info. This issue has been patched in version 2.11.2.
Configurations

Configuration 1 (hide)

cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:*

History

11 Mar 2026, 13:01

Type Values Removed Values Added
Summary
  • (es) Caddy es una plataforma de servidor extensible que usa TLS por defecto. Desde la versión 2.7.5 hasta antes de la versión 2.11.2, el comparador vars_regexp en vars.go:337 expande doblemente la entrada controlada por el usuario a través del reemplazador de Caddy. Cuando vars_regexp coincide con un marcador de posición como {http.request.header.X-Input}, el valor del encabezado se resuelve una vez (esperado), y luego se pasa por repl.ReplaceAll() de nuevo (el error). Esto significa que un atacante puede colocar {env.DATABASE_URL} o {file./etc /passwd} en un encabezado de solicitud y el servidor lo evaluará, filtrando variables de entorno, contenido de archivos e información del sistema. Este problema ha sido parcheado en la versión 2.11.2.
References () https://github.com/caddyserver/caddy/pull/5408 - () https://github.com/caddyserver/caddy/pull/5408 - Issue Tracking, Patch
References () https://github.com/caddyserver/caddy/releases/tag/v2.11.2 - () https://github.com/caddyserver/caddy/releases/tag/v2.11.2 - Product, Release Notes
References () https://github.com/caddyserver/caddy/security/advisories/GHSA-m2w3-8f23-hxxf - () https://github.com/caddyserver/caddy/security/advisories/GHSA-m2w3-8f23-hxxf - Exploit, Mitigation, Vendor Advisory
CPE cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.5
First Time Caddyserver
Caddyserver caddy

07 Mar 2026, 17:15

Type Values Removed Values Added
New CVE

Information

Published : 2026-03-07 17:15

Updated : 2026-03-11 13:01


NVD link : CVE-2026-30852

Mitre link : CVE-2026-30852

CVE.ORG link : CVE-2026-30852


JSON object : View

Products Affected

caddyserver

  • caddy
CWE
CWE-74

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CWE-200

Exposure of Sensitive Information to an Unauthorized Actor