{"id":"CVE-2026-77281","title":"Caddy is an extensible server platform that uses TLS by default","summary":"Caddy is an extensible server platform that uses TLS by default. In version 2.11.3 and earlier, three configuration-dependent weaknesses affect the handler and placeholder layer. In modules/caddyhttp/rewrite/rewrite.go, Rewrite.Rewrite()…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L","cwe":["CWE-94","CWE-178","CWE-770"],"vendor":"caddyserver","product":"caddy","affected":["caddy < 2.11.4"],"patched":["github.com/caddyserver/caddy/v2 2.11.4"],"published":"2026-09-17","updated":"2026-09-18","sourceUpdated":"2026-09-18T15:17:12.747","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-77281","references":[{"url":"https://github.com/caddyserver/caddy/commit/176b043b0104cee3f894023cd5a598ac29e404bb","label":"security-advisories@github.com"},{"url":"https://github.com/caddyserver/caddy/pull/7761","label":"security-advisories@github.com"},{"url":"https://github.com/caddyserver/caddy/releases/tag/v2.11.4","label":"security-advisories@github.com"},{"url":"https://github.com/caddyserver/caddy/security/advisories/GHSA-j8px-rmrx-76h9","label":"security-advisories@github.com"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77281"},{"url":"https://github.com/advisories/GHSA-j8px-rmrx-76h9"},{"url":"https://github.com/caddyserver/caddy"}],"tags":["nvd","cve.org","ghsa","go","osv"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-18T14:39:55.254322Z"},"epss":0.0036,"epssPercentile":0.2969,"aliases":["GHSA-j8px-rmrx-76h9"],"ecosystem":"go","ingestedAt":"2026-09-17T21:29:16.985Z","slug":"CVE-2026-77281","body":"## Overview\n\nCaddy is an extensible server platform that uses TLS by default. In version 2.11.3 and earlier, three configuration-dependent weaknesses affect the handler and placeholder layer. In modules/caddyhttp/rewrite/rewrite.go, Rewrite.Rewrite() can pass attacker-controlled replacement bytes through buildQueryString for a second placeholder expansion when a rewrite URI ends with a literal question mark, allowing injected environment or request-variable placeholders to disclose data and, when the file provider is registered, allowing injected file placeholders to disclose readable files. The  issue is fixed in version 2.11.4.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-77281)\n\nAffected packages:\n\n- `github.com/caddyserver/caddy/v2 <= 2.11.3`\n\nPatched in:\n\n- `github.com/caddyserver/caddy/v2 2.11.4`\n\nSource: https://github.com/advisories/GHSA-j8px-rmrx-76h9","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}