{"id":"DEBIAN-CVE-2026-27590","details":"Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's FastCGI path splitting logic computes the split index on a lowercased copy of the request path and then uses that byte index to slice the original path. This is unsafe for Unicode because `strings.ToLower()` can change UTF-8 byte length for some characters. As a result, Caddy can derive an incorrect `SCRIPT_NAME`/`SCRIPT_FILENAME` and `PATH_INFO`, potentially causing a request that contains `.php` to execute a different on-disk file than intended (path confusion). In setups where an attacker can control file contents (e.g., upload features), this can lead to unintended PHP execution of non-.php files (potential RCE depending on deployment). Version 2.11.1 fixes the issue.","modified":"2026-09-29T13:03:47.877248701Z","published":"2026-02-24T17:29:04.493Z","upstream":["CVE-2026-27590"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-27590"}],"affected":[{"package":{"name":"caddy","ecosystem":"Debian:12","purl":"pkg:deb/debian/caddy?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11.2-1","2.11.2-1~bpo13+1","2.11.4-1","2.6.2-10","2.6.2-11","2.6.2-12","2.6.2-13","2.6.2-14","2.6.2-5","2.6.2-6","2.6.2-6.1","2.6.2-7","2.6.2-8","2.6.2-9"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27590.json"}},{"package":{"name":"caddy","ecosystem":"Debian:13","purl":"pkg:deb/debian/caddy?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.6.2-12+deb13u1"}]}],"versions":["2.6.2-12"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27590.json"}},{"package":{"name":"caddy","ecosystem":"Debian:14","purl":"pkg:deb/debian/caddy?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11.2-1"}]}],"versions":["2.11.2-1~bpo13+1","2.6.2-12","2.6.2-13","2.6.2-14"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27590.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}