High 8.5Published Jul 8, 2026

CVE-2026-55999xorg-server / xwayland glamor font atlas Heap Buffer Overflow

Updated under an hour ago (Oct 28, 2026, 4:30 PM ET)

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It affects X.Org xorg-server and 2 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for X.Org xorg-server

Exploited in the last 30 days

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.

CVSS: 8.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-122
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: suse
NVD analysis: Analyzed
Record last updated: Jul 8, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

X.Org xorg-server x.org:xorg_server (from the name)	before 21.1.24	CNA record
X.Org xwayland x.org:xwayland (from the name)	before 24.1.13	CNA record
x.org x_server x.org:x_server	before 21.2.24	NVD
x.org xwayland x.org:xwayland	before 24.1.13	NVD

References

References

https://gitlab.freedesktop.org/xorg/xserver/-/commit/fbf7bac22e2c6bd627fb042742a23318263edae1	patch
https://www.openwall.com/lists/oss-security/2026/07/08/2	vendor-advisory, mailing-list, patch, third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.