{"id":"UBUNTU-CVE-2026-15747","details":"Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle. _csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden `csrf_token` input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle. An attacker able to query it can recover the token and pass csrf_protect validation.","modified":"2026-07-17T14:30:42.685038260Z","published":"2026-07-14T18:17:00Z","upstream":["CVE-2026-15747"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-15747"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-15747"},{"type":"REPORT","url":"https://lists.security.metacpan.org/cve-announce/msg/41816171/"},{"type":"REPORT","url":"https://github.com/mojolicious/mojo/commit/01921fbbbbeca2d1397e082d4a647f9b84c24e27.patch"},{"type":"REPORT","url":"https://metacpan.org/release/SRI/Mojolicious-9.48/changes"},{"type":"REPORT","url":"http://www.openwall.com/lists/oss-security/2026/07/14/16"}],"affected":[{"package":{"name":"libmojolicious-perl","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/libmojolicious-perl?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.15+dfsg-1","6.15+dfsg-1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"libmojolicious-perl","binary_version":"6.15+dfsg-1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-15747.json"}},{"package":{"name":"libmojolicious-perl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libmojolicious-perl?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.39+dfsg-1ubuntu1","7.43+dfsg-1ubuntu1","7.57+dfsg-1ubuntu1","7.59+dfsg-1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"libmojolicious-perl","binary_version":"7.59+dfsg-1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-15747.json"}},{"package":{"name":"libmojolicious-perl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libmojolicious-perl?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.22+dfsg-1","8.23+dfsg-1","8.26+dfsg-1","8.27+dfsg-1","8.32+dfsg-1","8.33+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_version":"8.33+dfsg-1","binary_name":"libmojolicious-perl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-15747.json"}},{"package":{"name":"libmojolicious-perl","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libmojolicious-perl?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.71+dfsg-1","9.22+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libmojolicious-perl","binary_version":"9.22+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-15747.json"}},{"package":{"name":"libmojolicious-perl","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libmojolicious-perl?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["9.33+dfsg-1","9.35+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_version":"9.35+dfsg-1","binary_name":"libmojolicious-perl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-15747.json"}},{"package":{"name":"libmojolicious-perl","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libmojolicious-perl?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["9.39+dfsg-1","9.42+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_version":"9.42+dfsg-1","binary_name":"libmojolicious-perl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-15747.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}