Description
Unchecked NULL pointer usage in LookupModMask in xkbcomp/expr.c in xkbcommon before 0.8.2 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file with invalid virtual modifiers.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libxkbcommon | 0.8.2-1 | — |
| Debian 13 | libxkbcommon | 0.8.2-1 | — |
| Debian 12 | libxkbcommon | 0.8.2-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libxkbcommon | 0.8.0-1ubuntu0.1 | USN-3786-2 |
| Ubuntu 16.04 LTS | libxkbcommon | 0.5.0-1ubuntu2.1 | USN-3786-1 |
| Ubuntu 14.04 LTS | libxkbcommon | 0.4.1-0ubuntu1.1 | USN-3786-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | gdm +2 | 1:3.28.2-16.el7 | RHSA-2019:2079 |
| RHEL 7 | libX11 +2 | 1.6.7-2.el7 | RHSA-2019:2079 |
| RHEL 7 | libxkbcommon +3 | 0.7.1-3.el7 | RHSA-2019:2079 |
| RHEL 7 | mesa-libGLw +1 | 8.0.0-5.el7 | RHSA-2019:2079 |
| RHEL 7 | xorg-x11-drv-ati | 19.0.1-2.el7 | RHSA-2019:2079 |
| RHEL 7 | xorg-x11-drv-vesa | 2.4.0-3.el7 | RHSA-2019:2079 |
| RHEL 7 | xorg-x11-drv-wacom +1 | 0.36.1-3.el7 | RHSA-2019:2079 |
| RHEL 7 | xorg-x11-server +9 | 1.20.4-7.el7 | RHSA-2019:2079 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 | libxkbcommon | 0.8.2-3.3.1 | SUSE-SU-2018:3685-1 |
| SLES 12 SP5 | libxkbcommon | 0.6.1-9.3.1 | SUSE-SU-2024:0037-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP5 | libxkbcommon | 0.6.1-9.3.1 | SUSE-SU-2024:0037-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | xorg-x11-server-Xdmx +8 | 1.20.4-7.amzn2.0.1 | ALAS2-2020-1433 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | gdm +2 | 1:3.28.2-16.el7 | ELSA-2019-2079 |
| Oracle Linux 7 | libX11 +2 | 1.6.7-2.el7 | ELSA-2019-2079 |
| Oracle Linux 7 | libxkbcommon +3 | 0.7.1-3.el7 | ELSA-2019-2079 |
| Oracle Linux 7 | mesa-libGLw +1 | 8.0.0-5.el7 | ELSA-2019-2079 |
| Oracle Linux 7 | xorg-x11-drv-ati | 19.0.1-2.el7 | ELSA-2019-2079 |
| Oracle Linux 7 | xorg-x11-drv-vesa | 2.4.0-3.el7 | ELSA-2019-2079 |
| Oracle Linux 7 | xorg-x11-drv-wacom +1 | 0.36.1-3.el7 | ELSA-2019-2079 |
| Oracle Linux 7 | xorg-x11-server-Xdmx +8 | 1.20.4-7.el7 | ELSA-2019-2079 |
Advisories 8
- RHSA-2019:2079 Red Hat Security Advisory: Xorg security and bug fix update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- USN-3786-1 libxkbcommon vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3786-2 libxkbcommon vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- SUSE-SU-2018:3685-1 Security update for libxkbcommon SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2024-0021 X.Org X11: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Feb 3, 2026
- SUSE-SU-2024:0037-1 Security update for libxkbcommon SUSE / openSUSE Security Updates · May 2, 2025
- ALAS2-2020-1433 Moderate: xorg-x11-server security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jun 3, 2020
- ELSA-2019-2079 Moderate: Xorg security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Aug 13, 2019
References
- GLSA-201810-05 vendor-advisory
- https://lists.freedesktop.org/archives/wayland-devel/2018-August/039243.html
- USN-3786-1 vendor-advisory
- https://github.com/xkbcommon/libxkbcommon/commit/4e2ee9c3f6050d773f8bbe05bc0edb17f1ff8371
- USN-3786-2 vendor-advisory
- RHSA-2019:2079 vendor-advisory