{"id":"UBUNTU-CVE-2026-18497","details":"A heap-buffer-overflow vulnerability exists in the nothings stb TrueType library, up to version 1.26, that is used for parsing TrueType font files. The vulnerability exists in the stbtt__GetGlyphShapeTT() function within the nothings stb_truetype.h library when parsing malformed TTF (TrueType Font) files. The vulnerability resides in the glyph data parsing path. An attacker can craft a malformed TTF file with an inflated endPtsOfContours value and truncate the remaining glyph data. When an application utilizing stb_truetype.h (such as various game engines or graphics software) attempts to load, bake, or render this malformed font via stbtt_GetGlyphShape(), the parser will attempt to read past the end of the glyph data buffer, triggering the out-of-bounds read.","modified":"2026-08-13T19:30:08.737543486Z","published":"2026-08-07T15:16:00Z","upstream":["CVE-2026-18497"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-18497"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-18497"},{"type":"REPORT","url":"https://cwe.mitre.org/data/definitions/122.html"},{"type":"REPORT","url":"https://github.com/nothings/stb"},{"type":"REPORT","url":"https://github.com/nothings/stb/issues/1905"},{"type":"REPORT","url":"https://kb.cert.org/vuls/id/987105"},{"type":"REPORT","url":"https://www.kb.cert.org/vuls/id/987105"}],"affected":[{"package":{"name":"libstb","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libstb?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0~git20190817.1.052dce1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.0~git20190817.1.052dce1-1","binary_name":"libstb0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18497.json"}},{"package":{"name":"libstb","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libstb?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0~git20200713.b42009b+ds-1","0.0~git20210910.af1a5bc+ds-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libstb0","binary_version":"0.0~git20210910.af1a5bc+ds-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18497.json"}},{"package":{"name":"libstb","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libstb?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0~git20230129.5736b15+ds-1","0.0~git20230129.5736b15+ds-1.1","0.0~git20230129.5736b15+ds-1.2"],"ecosystem_specific":{"binaries":[{"binary_version":"0.0~git20230129.5736b15+ds-1.2","binary_name":"libstb0t64"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18497.json"}},{"package":{"name":"libstb","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libstb?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0~git20241109.5c20573+ds-1","0.0~git20250907.fede005+ds-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libstb0t64","binary_version":"0.0~git20250907.fede005+ds-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18497.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}