CVEvulnerability

CVE-2026-30852

5.5 MEDIUM Published 2026-03-07 Modified 2026-06-17 Official page ↗
Status
Analyzed
Published
2026-03-07
Last modified
2026-06-17
Assigner
[email protected]
CVSS 4.0 ([email protected])
5.5 MEDIUM — CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weaknesses
CWE-200, CWE-74

Description

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.

Affected configurations

• caddyserver caddy (>= 2.7.5 < 2.11.2)

Related

Weakness · CWE (2)

  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor weakness
  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component weakness

References