{"id":"CVE-2026-27587","aliases":["GHSA-g7pc-pc7g-h8jh","GO-2026-4538"],"url":"https://o3.security/vulnerability/CVE-2026-27587","summary":"Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass","details":"Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP `path` request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences (`%xx`) it compares against the request's escaped path without lowercasing. An attacker can bypass path-based routing and any access controls attached to that route by changing the casing of the request path. Version 2.11.1 contains a fix for the issue.","published":"2026-02-24T16:26:40.222Z","modified":"2026-08-05T03:32:28.220290934Z","cvss":null,"epss":{"score":0.0037,"percentile":0.29733,"asOf":"2026-08-03"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/caddyserver/caddy/v2","fixedVersion":"2.11.1"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/caddyserver/caddy/releases/tag/v2.11.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27587.json"},{"type":"ADVISORY","url":"https://github.com/caddyserver/caddy/security/advisories/GHSA-g7pc-pc7g-h8jh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27587"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-05T03:32:28.220290934Z"}}