CVE-2026-55999
7.8
HIGH
CVSS 3.1
EPSS 0.21%
Description
Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks.
How to fix CVE-2026-55999
No fixed version has been published yet. Mitigate by removing the affected package or applying upstream guidance from the references below.
- Debian/xorg-server—no fix listed
- —no fix listed
Is CVE-2026-55999 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- from 0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |