{"id":"UBUNTU-CVE-2026-93712","details":"Dancer2 versions from 2.1.0 before 2.2.0 for Perl serve files from outside public_dir via relative path segments in the File route handler. The handler joins the request path onto public_dir without collapsing relative segments, and checks only that the result is a readable regular file. A request for `/../outside.txt` escapes public_dir, and percent-encoding the dots reaches the same file. The handler is off by default. An application is affected once it names File in route_handlers and sets static_handler to 0, which otherwise refuses a dot segment before the route runs. Any file the worker process can read is served to an unauthenticated request, including the application's config.yml above public_dir.","modified":"2026-09-24T02:03:13.161085242Z","published":"2026-09-22T01:16:00Z","upstream":["CVE-2026-93712"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-93712"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-93712"},{"type":"REPORT","url":"https://lists.security.metacpan.org/cve-announce/msg/43742973/"},{"type":"REPORT","url":"https://github.com/PerlDancer/Dancer2/security/advisories/GHSA-6xw8-v24c-m783"},{"type":"REPORT","url":"https://github.com/PerlDancer/Dancer2/commit/2446a09ffb83fef71cc75c327bd6e4b1f007b885.patch"},{"type":"REPORT","url":"https://metacpan.org/release/CROMEDOME/Dancer2-2.2.0/changes"},{"type":"REPORT","url":"http://www.openwall.com/lists/oss-security/2026/09/22/4"}],"affected":[{"package":{"name":"libdancer2-perl","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/libdancer2-perl?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.160003+dfsg-1","0.163000+dfsg-1","0.166001+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libdancer2-perl","binary_version":"0.166001+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93712.json"}},{"package":{"name":"libdancer2-perl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libdancer2-perl?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.205000+dfsg-1","0.205002+dfsg-1","0.205002+dfsg-2"],"ecosystem_specific":{"binaries":[{"binary_version":"0.205002+dfsg-2","binary_name":"libdancer2-perl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93712.json"}},{"package":{"name":"libdancer2-perl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libdancer2-perl?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.208001+dfsg-1","0.208002+dfsg-1","0.300000+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libdancer2-perl","binary_version":"0.300000+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93712.json"}},{"package":{"name":"libdancer2-perl","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libdancer2-perl?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.300005+dfsg-1","0.301004+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libdancer2-perl","binary_version":"0.301004+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93712.json"}},{"package":{"name":"libdancer2-perl","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libdancer2-perl?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.400001+dfsg-1","1.0.0+dfsg-1","1.1.0+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libdancer2-perl","binary_version":"1.1.0+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93712.json"}},{"package":{"name":"libdancer2-perl","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libdancer2-perl?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.2+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libdancer2-perl","binary_version":"1.1.2+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93712.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:N/A:N"},{"type":"Ubuntu","score":"medium"}]}