CVE-2026-50258
Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb key types due to unchecked shift levels
CVE-2026-50258 is fixed in 33 products on 1 platform, first by ALAS2023-2026-1790, released June 8, 2026. It is not reported as exploited. Patch Radar priority: High.
High
CVSS
7.8
Important
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0016
5th percentile
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.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| tigervnc · RHEL 8 | 0:1.15.0-10.el8_10 | RHSA-2026:28923 | Jun 25, 2026 |
| tigervnc · RHEL 9 | 0:1.15.0-7.el9_8.2 | RHSA-2026:29844 | Jun 29, 2026 |
| tigervnc · almalinux 8 | 1.15.0-10.el8_10 | ALSA-2026:28923 | Jun 24, 2026 |
| tigervnc · almalinux 9 | 1.15.0-7.el9_8.2 | ALSA-2026:29844 | Jun 25, 2026 |
| tigervnc · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc · ol 8 | 0:1.15.0-10.el8_10 | ELSA-2026-28923 | Jun 24, 2026 |
| tigervnc · ol 9 | 0:1.15.0-7.el9_8.2 | ELSA-2026-29844 | Jun 25, 2026 |
| tigervnc · rocky 8 | 0:1.15.0-10.el8_10 | RLSA-2026:28923 | Jun 25, 2026 |
| tigervnc · rocky 9 | 0:1.15.0-7.el9_8.2 | RLSA-2026:29844 | Jun 26, 2026 |
| tigervnc-debuginfo · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-debugsource · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-icons · RHEL 8 | 0:1.15.0-10.el8_10 | RHSA-2026:28923 | Jun 25, 2026 |
| tigervnc-icons · RHEL 9 | 0:1.15.0-7.el9_8.2 | RHSA-2026:29844 | Jun 29, 2026 |
| tigervnc-icons · almalinux 8 | 1.15.0-10.el8_10 | ALSA-2026:28923 | Jun 24, 2026 |
| tigervnc-icons · almalinux 9 | 1.15.0-7.el9_8.2 | ALSA-2026:29844 | Jun 25, 2026 |
| tigervnc-icons · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-icons · ol 8 | 0:1.15.0-10.el8_10 | ELSA-2026-28923 | Jun 24, 2026 |
| tigervnc-icons · ol 9 | 0:1.15.0-7.el9_8.2 | ELSA-2026-29844 | Jun 25, 2026 |
| tigervnc-license · RHEL 8 | 0:1.15.0-10.el8_10 | RHSA-2026:28923 | Jun 25, 2026 |
| tigervnc-license · RHEL 9 | 0:1.15.0-7.el9_8.2 | RHSA-2026:29844 | Jun 29, 2026 |
| tigervnc-license · almalinux 8 | 1.15.0-10.el8_10 | ALSA-2026:28923 | Jun 24, 2026 |
| tigervnc-license · almalinux 9 | 1.15.0-7.el9_8.2 | ALSA-2026:29844 | Jun 25, 2026 |
| tigervnc-license · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-license · ol 8 | 0:1.15.0-10.el8_10 | ELSA-2026-28923 | Jun 24, 2026 |
| tigervnc-license · ol 9 | 0:1.15.0-7.el9_8.2 | ELSA-2026-29844 | Jun 25, 2026 |
| tigervnc-selinux · RHEL 8 | 0:1.15.0-10.el8_10 | RHSA-2026:28923 | Jun 25, 2026 |
| tigervnc-selinux · RHEL 9 | 0:1.15.0-7.el9_8.2 | RHSA-2026:29844 | Jun 29, 2026 |
| tigervnc-selinux · almalinux 8 | 1.15.0-10.el8_10 | ALSA-2026:28923 | Jun 24, 2026 |
| tigervnc-selinux · almalinux 9 | 1.15.0-7.el9_8.2 | ALSA-2026:29844 | Jun 25, 2026 |
| tigervnc-selinux · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-selinux · ol 8 | 0:1.15.0-10.el8_10 | ELSA-2026-28923 | Jun 24, 2026 |
| tigervnc-selinux · ol 9 | 0:1.15.0-7.el9_8.2 | ELSA-2026-29844 | Jun 25, 2026 |
| tigervnc-server · RHEL 8 | 0:1.15.0-10.el8_10 | RHSA-2026:28923 | Jun 25, 2026 |
| tigervnc-server · RHEL 9 | 0:1.15.0-7.el9_8.2 | RHSA-2026:29844 | Jun 29, 2026 |
| tigervnc-server · almalinux 8 | 1.15.0-10.el8_10 | ALSA-2026:28923 | Jun 24, 2026 |
| tigervnc-server · almalinux 9 | 1.15.0-7.el9_8.2 | ALSA-2026:29844 | Jun 25, 2026 |
| tigervnc-server · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-server · ol 8 | 0:1.15.0-10.el8_10 | ELSA-2026-28923 | Jun 24, 2026 |
| tigervnc-server · ol 9 | 0:1.15.0-7.el9_8.2 | ELSA-2026-29844 | Jun 25, 2026 |
| tigervnc-server-debuginfo · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-server-minimal · RHEL 8 | 0:1.15.0-10.el8_10 | RHSA-2026:28923 | Jun 25, 2026 |
| tigervnc-server-minimal · RHEL 9 | 0:1.15.0-7.el9_8.2 | RHSA-2026:29844 | Jun 29, 2026 |
| tigervnc-server-minimal · almalinux 8 | 1.15.0-10.el8_10 | ALSA-2026:28923 | Jun 24, 2026 |
| tigervnc-server-minimal · almalinux 9 | 1.15.0-7.el9_8.2 | ALSA-2026:29844 | Jun 25, 2026 |
| tigervnc-server-minimal · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-server-minimal · ol 8 | 0:1.15.0-10.el8_10 | ELSA-2026-28923 | Jun 24, 2026 |
| tigervnc-server-minimal · ol 9 | 0:1.15.0-7.el9_8.2 | ELSA-2026-29844 | Jun 25, 2026 |
| tigervnc-server-minimal-debuginfo · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-server-module · RHEL 8 | 0:1.15.0-10.el8_10 | RHSA-2026:28923 | Jun 25, 2026 |
| tigervnc-server-module · RHEL 9 | 0:1.15.0-7.el9_8.2 | RHSA-2026:29844 | Jun 29, 2026 |
| tigervnc-server-module · almalinux 8 | 1.15.0-10.el8_10 | ALSA-2026:28923 | Jun 24, 2026 |
| tigervnc-server-module · almalinux 9 | 1.15.0-7.el9_8.2 | ALSA-2026:29844 | Jun 25, 2026 |
| tigervnc-server-module · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| tigervnc-server-module · ol 8 | 0:1.15.0-10.el8_10 | ELSA-2026-28923 | Jun 24, 2026 |
| tigervnc-server-module · ol 9 | 0:1.15.0-7.el9_8.2 | ELSA-2026-29844 | Jun 25, 2026 |
| tigervnc-server-module-debuginfo · amzn 2023 | 1.14.1-3.amzn2023.0.6 | ALAS2023-2026-1892 | Jun 22, 2026 |
| xorg-server · Debian 12.15 (bookworm) | 2:21.1.7-3+deb12u13 | DEBIAN-CVE-2026-50258 | Jun 24, 2026 |
| xorg-server · Debian 13.5 (trixie) | 2:21.1.16-1.3+deb13u3 | DEBIAN-CVE-2026-50258 | Jun 24, 2026 |
| xorg-server · Debian 14 | 2:21.1.23-1 | DEBIAN-CVE-2026-50258 | Jun 24, 2026 |
| xorg-x11-server · rocky 8 | 0:1.20.11-28.el8_10.2 | RLSA-2026:26709 | Jun 19, 2026 |
| xorg-x11-server · rocky 9 | 0:1.20.11-34.el9_8.2 | RLSA-2026:26610 | Jun 19, 2026 |
| xorg-x11-server-Xdmx · RHEL 8 | 0:1.20.11-28.el8_10.2 | RHSA-2026:26709 | Jun 24, 2026 |
| xorg-x11-server-Xdmx · RHEL 9 | 0:1.20.11-34.el9_8.2 | RHSA-2026:26610 | Jun 24, 2026 |
| xorg-x11-server-Xdmx · almalinux 8 | 1.20.11-28.el8_10.2 | ALSA-2026:26709 | Jun 17, 2026 |
| xorg-x11-server-Xdmx · almalinux 9 | 1.20.11-34.el9_8.2 | ALSA-2026:26610 | Jun 17, 2026 |
| xorg-x11-server-Xdmx · ol 8 | 0:1.20.11-28.el8_10.2 | ELSA-2026-26709 | Jun 17, 2026 |
| xorg-x11-server-Xdmx · ol 9 | 0:1.20.11-34.el9_8.2 | ELSA-2026-26610 | Jun 23, 2026 |
| xorg-x11-server-Xephyr · RHEL 8 | 0:1.20.11-28.el8_10.2 | RHSA-2026:26709 | Jun 24, 2026 |
| xorg-x11-server-Xephyr · RHEL 9 | 0:1.20.11-34.el9_8.2 | RHSA-2026:26610 | Jun 24, 2026 |
| xorg-x11-server-Xephyr · almalinux 8 | 1.20.11-28.el8_10.2 | ALSA-2026:26709 | Jun 17, 2026 |
| xorg-x11-server-Xephyr · almalinux 9 | 1.20.11-34.el9_8.2 | ALSA-2026:26610 | Jun 17, 2026 |
| xorg-x11-server-Xephyr · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-Xephyr · ol 8 | 0:1.20.11-28.el8_10.2 | ELSA-2026-26709 | Jun 17, 2026 |
| xorg-x11-server-Xephyr · ol 9 | 0:1.20.11-34.el9_8.2 | ELSA-2026-26610 | Jun 23, 2026 |
| xorg-x11-server-Xephyr-debuginfo · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-Xnest · RHEL 8 | 0:1.20.11-28.el8_10.2 | RHSA-2026:26709 | Jun 24, 2026 |
| xorg-x11-server-Xnest · RHEL 9 | 0:1.20.11-34.el9_8.2 | RHSA-2026:26610 | Jun 24, 2026 |
| xorg-x11-server-Xnest · almalinux 8 | 1.20.11-28.el8_10.2 | ALSA-2026:26709 | Jun 17, 2026 |
| xorg-x11-server-Xnest · almalinux 9 | 1.20.11-34.el9_8.2 | ALSA-2026:26610 | Jun 17, 2026 |
| xorg-x11-server-Xnest · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-Xnest · ol 8 | 0:1.20.11-28.el8_10.2 | ELSA-2026-26709 | Jun 17, 2026 |
| xorg-x11-server-Xnest · ol 9 | 0:1.20.11-34.el9_8.2 | ELSA-2026-26610 | Jun 23, 2026 |
| xorg-x11-server-Xnest-debuginfo · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-Xorg · RHEL 8 | 0:1.20.11-28.el8_10.2 | RHSA-2026:26709 | Jun 24, 2026 |
| xorg-x11-server-Xorg · RHEL 9 | 0:1.20.11-34.el9_8.2 | RHSA-2026:26610 | Jun 24, 2026 |
| xorg-x11-server-Xorg · almalinux 8 | 1.20.11-28.el8_10.2 | ALSA-2026:26709 | Jun 17, 2026 |
| xorg-x11-server-Xorg · almalinux 9 | 1.20.11-34.el9_8.2 | ALSA-2026:26610 | Jun 17, 2026 |
| xorg-x11-server-Xorg · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-Xorg · ol 8 | 0:1.20.11-28.el8_10.2 | ELSA-2026-26709 | Jun 17, 2026 |
| xorg-x11-server-Xorg · ol 9 | 0:1.20.11-34.el9_8.2 | ELSA-2026-26610 | Jun 23, 2026 |
| xorg-x11-server-Xorg-debuginfo · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-Xvfb · RHEL 8 | 0:1.20.11-28.el8_10.2 | RHSA-2026:26709 | Jun 24, 2026 |
| xorg-x11-server-Xvfb · RHEL 9 | 0:1.20.11-34.el9_8.2 | RHSA-2026:26610 | Jun 24, 2026 |
| xorg-x11-server-Xvfb · almalinux 8 | 1.20.11-28.el8_10.2 | ALSA-2026:26709 | Jun 17, 2026 |
| xorg-x11-server-Xvfb · almalinux 9 | 1.20.11-34.el9_8.2 | ALSA-2026:26610 | Jun 17, 2026 |
| xorg-x11-server-Xvfb · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-Xvfb · ol 8 | 0:1.20.11-28.el8_10.2 | ELSA-2026-26709 | Jun 17, 2026 |
| xorg-x11-server-Xvfb · ol 9 | 0:1.20.11-34.el9_8.2 | ELSA-2026-26610 | Jun 23, 2026 |
| xorg-x11-server-Xvfb-debuginfo · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-Xwayland · RHEL 10 | 24.1.5-6.el10_0.1 | RHSA-2026:36798 | Jun 24, 2026 |
| xorg-x11-server-Xwayland · RHEL 8 | 0:21.1.3-20.el8_10.2 | RHSA-2026:26562 | Jun 24, 2026 |
| xorg-x11-server-Xwayland · RHEL 9 | 0:24.1.9-4.el9_8.2 | RHSA-2026:26590 | Jun 24, 2026 |
| xorg-x11-server-Xwayland · almalinux 10 | 24.1.9-4.el10_2.2 | ALSA-2026:26566 | Jun 17, 2026 |
| xorg-x11-server-Xwayland · almalinux 8 | 21.1.3-20.el8_10.2 | ALSA-2026:26562 | Jun 17, 2026 |
| xorg-x11-server-Xwayland · almalinux 9 | 24.1.9-4.el9_8.2 | ALSA-2026:26590 | Jun 17, 2026 |
| xorg-x11-server-Xwayland · amzn 2023 | 24.1.3-1.amzn2023.0.5 | ALAS2023-2026-1789 | Jun 8, 2026 |
| xorg-x11-server-Xwayland · ol 10 | 0:24.1.9-4.el10_2.2 | ELSA-2026-26566 | Jul 16, 2026 |
| xorg-x11-server-Xwayland · ol 8 | 0:21.1.3-20.el8_10.2 | ELSA-2026-26562 | Jun 17, 2026 |
| xorg-x11-server-Xwayland · ol 9 | 0:24.1.9-4.el9_8.2 | ELSA-2026-26590 | Jun 23, 2026 |
| xorg-x11-server-Xwayland · rocky 10 | 0:24.1.9-4.el10_2.2 | RLSA-2026:26566 | Jun 24, 2026 |
| xorg-x11-server-Xwayland · rocky 8 | 0:21.1.3-20.el8_10.2 | RLSA-2026:26562 | Jun 19, 2026 |
| xorg-x11-server-Xwayland · rocky 9 | 0:24.1.9-4.el9_8.2 | RLSA-2026:26590 | Jun 19, 2026 |
| xorg-x11-server-Xwayland-debuginfo · amzn 2023 | 24.1.3-1.amzn2023.0.5 | ALAS2023-2026-1789 | Jun 8, 2026 |
| xorg-x11-server-Xwayland-debugsource · amzn 2023 | 24.1.3-1.amzn2023.0.5 | ALAS2023-2026-1789 | Jun 8, 2026 |
| xorg-x11-server-Xwayland-devel · RHEL 9 | 0:24.1.9-4.el9_8.2 | RHSA-2026:26590 | Jun 24, 2026 |
| xorg-x11-server-Xwayland-devel · almalinux 10 | 24.1.9-4.el10_2.2 | ALSA-2026:26566 | Jun 17, 2026 |
| xorg-x11-server-Xwayland-devel · almalinux 9 | 24.1.9-4.el9_8.2 | ALSA-2026:26590 | Jun 17, 2026 |
| xorg-x11-server-Xwayland-devel · amzn 2023 | 24.1.3-1.amzn2023.0.5 | ALAS2023-2026-1789 | Jun 8, 2026 |
| xorg-x11-server-Xwayland-devel · ol 10 | 0:24.1.9-4.el10_2.2 | ELSA-2026-26566 | Jul 16, 2026 |
| xorg-x11-server-Xwayland-devel · ol 9 | 0:24.1.9-4.el9_8.2 | ELSA-2026-26590 | Jun 23, 2026 |
| xorg-x11-server-common · RHEL 8 | 0:1.20.11-28.el8_10.2 | RHSA-2026:26709 | Jun 24, 2026 |
| xorg-x11-server-common · RHEL 9 | 0:1.20.11-34.el9_8.2 | RHSA-2026:26610 | Jun 24, 2026 |
| xorg-x11-server-common · almalinux 8 | 1.20.11-28.el8_10.2 | ALSA-2026:26709 | Jun 17, 2026 |
| xorg-x11-server-common · almalinux 9 | 1.20.11-34.el9_8.2 | ALSA-2026:26610 | Jun 17, 2026 |
| xorg-x11-server-common · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-common · ol 8 | 0:1.20.11-28.el8_10.2 | ELSA-2026-26709 | Jun 17, 2026 |
| xorg-x11-server-common · ol 9 | 0:1.20.11-34.el9_8.2 | ELSA-2026-26610 | Jun 23, 2026 |
| xorg-x11-server-debuginfo · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-debugsource · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-devel · RHEL 8 | 0:1.20.11-28.el8_10.2 | RHSA-2026:26709 | Jun 24, 2026 |
| xorg-x11-server-devel · RHEL 9 | 0:1.20.11-34.el9_8.2 | RHSA-2026:26610 | Jun 24, 2026 |
| xorg-x11-server-devel · almalinux 8 | 1.20.11-28.el8_10.2 | ALSA-2026:26709 | Jun 17, 2026 |
| xorg-x11-server-devel · almalinux 9 | 1.20.11-34.el9_8.2 | ALSA-2026:26610 | Jun 17, 2026 |
| xorg-x11-server-devel · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-devel · ol 8 | 0:1.20.11-28.el8_10.2 | ELSA-2026-26709 | Jun 17, 2026 |
| xorg-x11-server-devel · ol 9 | 0:1.20.11-34.el9_8.2 | ELSA-2026-26610 | Jun 23, 2026 |
| xorg-x11-server-source · RHEL 8 | 0:1.20.11-28.el8_10.2 | RHSA-2026:26709 | Jun 24, 2026 |
| xorg-x11-server-source · RHEL 9 | 0:1.20.11-34.el9_8.2 | RHSA-2026:26610 | Jun 24, 2026 |
| xorg-x11-server-source · almalinux 8 | 1.20.11-28.el8_10.2 | ALSA-2026:26709 | Jun 17, 2026 |
| xorg-x11-server-source · almalinux 9 | 1.20.11-34.el9_8.2 | ALSA-2026:26610 | Jun 17, 2026 |
| xorg-x11-server-source · amzn 2023 | 21.1.13-5.amzn2023.0.10 | ALAS2023-2026-1790 | Jun 8, 2026 |
| xorg-x11-server-source · ol 8 | 0:1.20.11-28.el8_10.2 | ELSA-2026-26709 | Jun 17, 2026 |
| xorg-x11-server-source · ol 9 | 0:1.20.11-34.el9_8.2 | ELSA-2026-26610 | Jun 23, 2026 |
| xwayland · Debian 14 | 2:24.1.12-1 | DEBIAN-CVE-2026-50258 | Jun 24, 2026 |
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