Description
In X.Org X server 20.11 through 21.1.16, when a client application uses easystroke for mouse gestures, the main thread modifies various data structures used by the input thread without acquiring a lock, aka a race condition. In particular, AttachDevice in dix/devices.c does not acquire an input lock.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| X.org | X server | 20.11 – ≤ 21.1.16 | — |
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 | xorg-server | 2:21.1.16-1.1 | — |
| Debian 13 | xorg-server | 2:21.1.16-1.1 | — |
| Debian 12 | xorg-server | 2:21.1.7-3+deb12u13 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | xwayland | No fix yet | — |
| Ubuntu 26.04 LTS | xorg-server | 2:21.1.18-1ubuntu1 | — |
| Ubuntu 26.04 LTS | xwayland | No fix yet | — |
| Ubuntu 25.10 | xorg-server | 2:21.1.18-1ubuntu1 | — |
| Ubuntu 25.10 | xwayland | No fix yet | — |
| Ubuntu 24.04 LTS | xwayland +1 | No fix yet | — |
| Ubuntu 22.04 LTS | xwayland +1 | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | xorg-server | No fix yet | — |
| Ubuntu Pro 18.04 LTS | xorg-server +1 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | xorg-server +1 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | xorg-server | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | xorg-x11-server | 21.1.11-150600.5.9.1 | SUSE-SU-2025:0984-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xorg-x11-server | 21.1.15-3.1 | openSUSE-SU-2025:14916-1 |
| openSUSE Leap 15.6 | xorg-x11-server | 21.1.11-150600.5.9.1 | SUSE-SU-2025:0984-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | xorg-x11-server-Xorg +6 | 21.1.13-5.amzn2023.0.5 | ALAS2023-2025-939 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | xorg-server | 21.1.20-r0 | — |
Advisories 4
- WID-SEC-2025-0572 X.Org X11: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Aug 12, 2026
- SUSE-SU-2025:0984-1 Security update for xorg-x11-server SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14916-1 xorg-x11-server-21.1.15-3.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2023-2025-939 Moderate: xorg-x11-server security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Apr 14, 2025
References
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1081338
- https://gitlab.freedesktop.org/xorg/xserver/-/issues/1260
- https://bugs.debian.org/cgi-bin/bugreport.cgi?att=1;bug=1081338;filename=dix-Hold-input-lock-for-AttachDevice.patch;msg=5
- https://gitlab.freedesktop.org/xorg/xserver/-/commit/dc7cb45482cea6ccec22d117ca0b489500b4d0a0