5.5
Medium
CVE-2026-30852 Caddy is an extensible server platform that uses TLS by default
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 products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| caddy 2.7 | 2.7.5 → < 2.11.2 | 2.11.2 |
Other CVEs of caddy
The 17 CVEs of caddy →
CVE-2026-55458
Caddy: RFC 7230 §6.1 compliance issue / Hop-by-hop headers that leak through
2.9
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CVE-2026-92700
Caddy is an extensible server platform that uses TLS by default
6.3
Medium
CVE-2026-92284
Caddy is an extensible server platform that uses TLS by default
6.9
Medium
CVE-2026-77281
Caddy is an extensible server platform that uses TLS by default
6.5
Medium