{"id":"UBUNTU-CVE-2026-56003","details":"A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X server.","modified":"2026-07-21T13:10:19.405526932Z","published":"2026-07-08T10:16:00Z","related":["USN-8560-1"],"upstream":["CVE-2026-56003"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-56003"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-56003"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2026/07/08/1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8560-1"}],"affected":[{"package":{"name":"libxfont","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/libxfont?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:1.4.7-1ubuntu0.4+esm2"}]}],"versions":["1:1.4.6-1","1:1.4.6-1ubuntu1","1:1.4.7-1","1:1.4.7-1ubuntu0.1","1:1.4.7-1ubuntu0.2","1:1.4.7-1ubuntu0.3","1:1.4.7-1ubuntu0.4"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro","binaries":[{"binary_name":"libxfont1","binary_version":"1:1.4.7-1ubuntu0.4+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56003.json"}},{"package":{"name":"libxfont","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/libxfont?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:1.5.1-1ubuntu0.16.04.4+esm2"}]}],"versions":["1:1.5.1-1","1:1.5.1-1ubuntu0.16.04.1","1:1.5.1-1ubuntu0.16.04.2","1:1.5.1-1ubuntu0.16.04.3","1:1.5.1-1ubuntu0.16.04.4"],"ecosystem_specific":{"binaries":[{"binary_name":"libxfont1","binary_version":"1:1.5.1-1ubuntu0.16.04.4+esm2"}],"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-2026-56003.json"}},{"package":{"name":"libxfont2","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/libxfont2?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:2.0.1-3~ubuntu16.04.1","1:2.0.1-3~ubuntu16.04.2","1:2.0.1-3~ubuntu16.04.3"],"ecosystem_specific":{"binaries":[{"binary_name":"libxfont2","binary_version":"1:2.0.1-3~ubuntu16.04.3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56003.json"}},{"package":{"name":"libxfont","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/libxfont?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2.0.3-1ubuntu0.1~esm2"}]}],"versions":["1:2.0.1-3ubuntu1","1:2.0.1-4","1:2.0.1-4ubuntu1","1:2.0.3-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxfont2","binary_version":"1:2.0.3-1ubuntu0.1~esm2"}],"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-2026-56003.json"}},{"package":{"name":"libxfont","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/libxfont?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2.0.3-1ubuntu0.20.04.1~esm2"}]}],"versions":["1:2.0.3-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxfont2","binary_version":"1:2.0.3-1ubuntu0.20.04.1~esm2"}],"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-2026-56003.json"}},{"package":{"name":"libxfont","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libxfont?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2.0.5-1ubuntu0.2"}]}],"versions":["1:2.0.4-1build3","1:2.0.5-1","1:2.0.5-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"1:2.0.5-1ubuntu0.2","binary_name":"libxfont2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56003.json"}},{"package":{"name":"libxfont","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libxfont?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2.0.6-1+deb13u1build0.24.04.2"}]}],"versions":["1:2.0.6-1","1:2.0.6-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxfont2","binary_version":"1:2.0.6-1+deb13u1build0.24.04.2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56003.json"}},{"package":{"name":"libxfont","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/libxfont?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:2.0.6-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxfont2","binary_version":"1:2.0.6-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56003.json"}},{"package":{"name":"libxfont","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libxfont?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2.0.6-2ubuntu0.2"}]}],"versions":["1:2.0.6-1build1","1:2.0.6-1build2","1:2.0.6-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libxfont2","binary_version":"1:2.0.6-2ubuntu0.2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56003.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}