{"id":"CVE-2026-30852","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-30852","generatedAt":"2026-10-28T03:26:28.518Z","title":"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.","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.","published":"2026-03-07T17:15:53.000Z","lastModified":"2026-06-17T10:33:02.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":5.5,"severity":"MEDIUM","vector":"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/M"},"cwe":["CWE-74","CWE-200"],"affected":["caddyserver/caddy"],"epss":{"score":0.00436,"percentile":0.37663,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.44%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/caddyserver/caddy/pull/5408","tags":["Issue Tracking","Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/caddyserver/caddy/releases/tag/v2.11.2","tags":["Product","Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/caddyserver/caddy/security/advisories/GHSA-m2w3-8f23-hxxf","tags":["Exploit","Mitigation","Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-30852","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}