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High 7.8Published Jun 5, 2026

CVE-2026-50259A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland.

Updated under an hour ago ()

Does this affect you?

It affects x.org x_server and 2 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.

CVSS
7.8 HIGH (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-121
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Modified
Record last updated
Aug 5, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
x.org x_server
x.org:x_server
before 21.1.23
NVD
x.org xwayland
x.org:xwayland
before 24.1.12
NVD
redhat enterprise_linux
redhat:enterprise_linux
7.0; 8.0; 9.0; 10.0
NVD

References

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.

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