CVE search · CVE-2026-30852
CVE-2026-30852
medium 5.5
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.
Details
- Status
- Analyzed
- Published
- Last changed
- Source
- security-advisories@github.com
Severity
| Version | Score | Vector | Source |
|---|---|---|---|
| CVSS 4.0 | medium 5.5 | 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 |
security-advisories@github.comSecondary |
| CVSS 3.1 | high 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
nvd@nist.govPrimary |
Affected products
Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.
- caddyserver · caddy
References
- https://github.com/caddyserver/caddy/pull/5408Issue TrackingPatch
- https://github.com/caddyserver/caddy/releases/tag/v2.11.2ProductRelease Notes
- https://github.com/caddyserver/caddy/security/advisories/GHSA-m2w3-8f23-hxxfExploitMitigationVendor Advisory