{"id":"AZL-101730","summary":"CVE-2026-59679 affecting package libXfont2 2.0.8-1","details":"fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) indexes the per-character encoding[] array using num_chars from the FS_QueryXBitmaps16 reply, but that array was allocated with a size derived from num_extents in the separate FS_QueryXExtents16 reply. The two CARD32 fields are never cross-checked.\nA malicious or compromised font server can send a small num_extents (e.g. 1) in the extents reply, then a large num_chars (e.g. 100000) in the bitmaps reply. This causes attacker-controlled out-of-bounds heap read and writes.","modified":"2026-09-19T05:33:49Z","published":"2026-09-10T09:17:02Z","upstream":["CVE-2026-59679"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59679"}],"affected":[{"package":{"name":"libXfont2","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/libXfont2"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2.0.8-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-101730.json"}}],"schema_version":"1.9.0"}