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.

INFO

Published Date :

2026-03-07T16:28:26.894Z

Last Modified :

2026-03-09T18:24:55.495Z

Source :

GitHub_M
AFFECTED PRODUCTS

The following products are affected by CVE-2026-30852 vulnerability.

Vendors Products
Caddyserver
  • Caddy
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-30852.

URL Resource
https://github.com/caddyserver/caddy/pull/5408 cve-icon cve-icon
https://github.com/caddyserver/caddy/releases/tag/v2.11.2 cve-icon cve-icon
https://github.com/caddyserver/caddy/security/advisories/GHSA-m2w3-8f23-hxxf cve-icon cve-icon
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CVSS Vulnerability Scoring System

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Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact