{"cve":"CVE-2026-44950","nvd":{"published":"2026-09-10T09:17:02.490","modified":"2026-09-10T19:17:27.730","status":"Awaiting Analysis","description":"fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) copies each glyph's bitmap into a single buffer. Existing checks validates only that the source slice (position, length) lies within the source bitmap buffer. It does not check whether the running destination cursor has exceeded the allocation.\n\nA malicious font server can send overlapping source offsets -- for example 1000 glyphs each referencing {position:0, length:64} with nbytes=64. Each individual source range passes the existing validation, but the cumulative writes total 64000 bytes into a 64-byte destination buffer. This is a heap buffer overflow with attacker-controlled content.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","score":9.5},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","score":9.0},"cwes":["CWE-122"],"references":["https://bugzilla.suse.com/show_bug.cgi?id=CVE-2026-44950"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:52:53.108888569+00:00"},"epss":{"cve":"CVE-2026-44950","score":0.00262,"percentile":0.18095,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}