CVE-2026-30852
- Source
- https://cve.org/CVERecord?id=CVE-2026-30852
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-30852.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-30852
- Aliases
- Downstream
- Related
- Published
- 2026-03-07T16:28:26.894Z
- Modified
- 2026-04-10T05:41:56.787562Z
- Severity
-
- 5.5 (Medium) CVSS_V4 - 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 CVSS Calculator
- Summary
- Caddy: vars_regexp double-expands user input, leaking env vars and files
- Details
-
Caddy is an extensible server platform that uses TLS by default. From version 2.7.5 to before version 2.11.2, the varsregexp matcher in vars.go:337 double-expands user-controlled input through the Caddy replacer. When varsregexp 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.
- Database specific
{ "cna_assigner": "GitHub_M", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/30xxx/CVE-2026-30852.json", "cwe_ids": [ "CWE-200", "CWE-74" ] }- References
-
- https://github.com/caddyserver/caddy/releases/tag/v2.11.2
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/30xxx/CVE-2026-30852.json
- https://github.com/caddyserver/caddy/security/advisories/GHSA-m2w3-8f23-hxxf
- https://nvd.nist.gov/vuln/detail/CVE-2026-30852
- https://github.com/caddyserver/caddy/pull/5408