{"id":"USN-8560-1","summary":"libxfont vulnerabilities","details":"It was discovered that libXfont incorrectly handled scaling bitmap\nfonts, leading to a heap buffer overflow. An attacker able to access\nthe X server could use this issue to cause libXfont to crash,\nresulting in a denial of service, or possibly execute arbitrary code.\n(CVE-2026-56001)\n\nIt was discovered that libXfont did not properly check glyph bounds\nwhen reading PCF fonts, leading to a heap buffer overflow. An\nauthenticated X client could use this issue to cause libXfont to\ncrash, resulting in a denial of service, or possibly execute arbitrary\ncode. (CVE-2026-56002)\n\nIt was discovered that libXfont did not properly check the size of the\nproperty buffer when parsing PCF fonts, leading to a heap buffer\noverflow. An authenticated X client could use this issue to cause\nlibXfont to crash, resulting in a denial of service, or possibly\nexecute arbitrary code. (CVE-2026-56003)","modified":"2026-07-21T13:20:11.018061694Z","published":"2026-07-20T12:28:31Z","related":["UBUNTU-CVE-2026-56001","UBUNTU-CVE-2026-56002","UBUNTU-CVE-2026-56003"],"upstream":["CVE-2017-16611","CVE-2026-56001","CVE-2026-56002","CVE-2026-56003","UBUNTU-CVE-2017-16611","UBUNTU-CVE-2026-56001","UBUNTU-CVE-2026-56002","UBUNTU-CVE-2026-56003"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8560-1"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2017-16611"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-56001"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-56002"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-56003"}],"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":{"binaries":[{"binary_name":"libxfont1","binary_version":"1:1.4.7-1ubuntu0.4+esm2"}],"availability":"Available 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