{"id":"UBUNTU-CVE-2026-13601","details":"A flaw was found in Yelp due to an overly permissive Content Security Policy (CSP) implementation provided by yelp-xsl. A malicious Flatpak application can open crafted help content through the OpenURI portal. By embedding an untrusted CSS stylesheet within a structured SVG document, attacker-controlled content can bypass Flatpak's intended sandbox isolation, allowing Yelp to evaluate local XML inclusions and disclose arbitrary user-readable host files through remote CSS resource requests. This may result in the unauthorized disclosure of sensitive information.","modified":"2026-08-17T02:45:04.258940530Z","published":"2026-06-29T10:16:00Z","related":["USN-8627-1"],"upstream":["CVE-2026-13601"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-13601"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-13601"},{"type":"REPORT","url":"https://blogs.gnome.org/mcatanzaro/2026/05/11/flatpak-sandbox-escape-via-yelp/"},{"type":"REPORT","url":"https://gitlab.gnome.org/GNOME/yelp/-/work_items/238"},{"type":"REPORT","url":"https://access.redhat.com/security/cve/CVE-2026-13601"},{"type":"REPORT","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-13601.json"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8627-1"}],"affected":[{"package":{"name":"yelp","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/yelp?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.18.1-1ubuntu4+esm1"}]}],"versions":["3.16.1-1ubuntu1","3.16.1-1ubuntu2","3.18.1-1ubuntu2","3.18.1-1ubuntu3","3.18.1-1ubuntu4"],"ecosystem_specific":{"binaries":[{"binary_name":"libyelp0","binary_version":"3.18.1-1ubuntu4+esm1"},{"binary_name":"yelp","binary_version":"3.18.1-1ubuntu4+esm1"}],"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-13601.json"}},{"package":{"name":"yelp","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/yelp?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.26.0-1ubuntu2+esm1"}]}],"versions":["3.26.0-1ubuntu1","3.26.0-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_version":"3.26.0-1ubuntu2+esm1","binary_name":"libyelp0"},{"binary_name":"yelp","binary_version":"3.26.0-1ubuntu2+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-13601.json"}},{"package":{"name":"yelp","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/yelp?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.36.2-0ubuntu1.1+esm1"}]}],"versions":["3.34.0-1","3.36.0-1","3.36.2-0ubuntu1","3.36.2-0ubuntu1.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyelp0","binary_version":"3.36.2-0ubuntu1.1+esm1"},{"binary_version":"3.36.2-0ubuntu1.1+esm1","binary_name":"yelp"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-13601.json"}},{"package":{"name":"yelp","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/yelp?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"42.1-1ubuntu0.2"}]}],"versions":["40.stable-1build1","41.1-1","41.2-1","42~beta-2","42.0-1","42.1-1","42.1-1ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"42.1-1ubuntu0.2","binary_name":"libyelp0"},{"binary_version":"42.1-1ubuntu0.2","binary_name":"yelp"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-13601.json"}},{"package":{"name":"yelp","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/yelp?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"42.2-1ubuntu0.24.04.2"}]}],"versions":["42.2-1","42.2-1build1","42.2-1build2","42.2-1ubuntu0.24.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyelp0","binary_version":"42.2-1ubuntu0.24.04.2"},{"binary_name":"yelp","binary_version":"42.2-1ubuntu0.24.04.2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-13601.json"}},{"package":{"name":"yelp","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/yelp?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["42.2-2","42.2-4","42.2-4build1","42.3-1","42.3-3ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyelp0","binary_version":"42.3-3ubuntu1"},{"binary_name":"yelp","binary_version":"42.3-3ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-13601.json"}},{"package":{"name":"yelp","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/yelp?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"49.0-5ubuntu0.1"}]}],"versions":["42.3-3ubuntu1","49.0-4","49.0-5"],"ecosystem_specific":{"binaries":[{"binary_name":"libyelp-1-0","binary_version":"49.0-5ubuntu0.1"},{"binary_version":"49.0-5ubuntu0.1","binary_name":"yelp"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-13601.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}