CVE-2026-50258

highpriority · track · 0EPSS 0.002 · 5 %ileDEEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.16% (5th) EPSS

CVSS 7.8 · high

Is it mine?

62 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. The X server has multiple stack buffers sized XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify or clamp non-canonical key types to XkbMaxShiftLevel. A client can change key types to excessive shift levels and trigger stack overflows. This is caused by an incomplete fix of CVE-2025-26597. This may be used to crash the server, or for privilege escalation if the X server runs as root.

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · secalert@redhat.com USexploitability 1.8 · impact 5.9

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondaryexploitability 1.8 · impact 5.9

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-121USCWE-121US

affected products (62)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Fedora Linuxall versionscert_bundDEcpe:/o:fedoraproject:fedora:-
Gentoo Linuxall versionscert_bundDEcpe:/o:gentoo:linux:-
IBM Power Hardware Management Console V10.3.1050.0-V10.3.1064.1all versionscert_bundDEcpe:/a:ibm:hardware_management_console:v10.3.1050.0_-_v10.3.1064.1
IBM Power Hardware Management Console V11.1.1110.0-V11.1.1112.2all versionscert_bundDEcpe:/a:ibm:hardware_management_console:v11.1.1110.0_-_v11.1.1112.2
Microsoft Azure Linux azl3all versionscert_bundDEcpe:/o:microsoft:azure_linux:azl3
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
RESF Rocky Linuxall versionscert_bundDEcpe:/o:resf:rocky_linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Open Source X.Org X11≤ Server <21.1.23cert_bundDE
Open Source Xwayland< 24.1.12cert_bundDE
Red Hat Red Hat Enterprise Linux 10< 0:24.1.9-4.el10_2.2enisa_euvdEU
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support< 0:24.1.5-6.el10_0.1enisa_euvdEU
Red Hat Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION< 0:1.1.0-25.el6_10.18enisa_euvdEU
Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support< 0:1.20.4-35.el7_9enisa_euvdEU
Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support< 0:1.8.0-36.el7_9.5enisa_euvdEU
Red Hat Red Hat Enterprise Linux 8< 0:1.15.0-10.el8_10enisa_euvdEU
Red Hat Red Hat Enterprise Linux 8< 0:1.20.11-28.el8_10.2enisa_euvdEU
Red Hat Red Hat Enterprise Linux 8< 0:21.1.3-20.el8_10.2enisa_euvdEU

showing 20 of 62

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-1774X.Org X11 und Xwayland: Mehrere SchwachstellenDeutsch2026-06-01csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in X.Org X11 und Xwayland ausnutzen, um Informationen offenzulegen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, und um einen nicht näher spezifizierten Angriff durchzuführen.
WID-SEC-W-2026-2455Oracle Solaris Drittanbieterkomponenten: Mehrere SchwachstellenDeutsch2026-07-21csaf · cert_bundDE
Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in verschiedenen Komponenten von Drittanbietern in Oracle Solaris ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund NVD CVE.org MITRE

published 2026-06-05modified 2026-10-08

references (77)

External citations — patches, advisories, analysis.

scry

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