Description
X.org libXtst before 1.2.3 allows remote X servers to cause a denial of service (infinite loop) via a reply in the (1) XRecordStartOfData, (2) XRecordEndOfData, or (3) XRecordClientDied category without a client sequence and with attached data.
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 | libxtst | 2:1.2.3-1 | — |
| Debian 13 | libxtst | 2:1.2.3-1 | — |
| Debian 12 | libxtst | 2:1.2.3-1 | — |
| Debian 7 | libxtst | 2:1.2.1-1+deb7u2 | DLA-686-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libxtst | 2:1.2.5-1ubuntu1 | USN-8939-1 |
| Ubuntu 26.04 LTS | libxtst | 2:1.2.5-1ubuntu0.1 | USN-8939-1 |
| Ubuntu 24.04 LTS | libxtst | 2:1.2.3-1.1ubuntu0.1 | USN-8939-1 |
| Ubuntu 22.04 LTS | libxtst | 2:1.2.3-1ubuntu0.22.04.1 | USN-8939-1 |
| Ubuntu 20.04 LTS | libxtst | 2:1.2.3-1 | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libxtst | 2:1.2.3-1 | — |
| Ubuntu Pro 20.04 LTS | libxtst | 2:1.2.3-1ubuntu0.20.04.1~esm1 | USN-8939-1 |
| Ubuntu Pro 18.04 LTS | libxtst | 2:1.2.3-1ubuntu0.18.04.1~esm1 | USN-8939-1 |
| Ubuntu Pro 16.04 LTS | libxtst | 2:1.2.2-1ubuntu0.1~esm1 | USN-8939-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | libX11 | 1.6.2-8.1 | SUSE-SU-2016:2828-1 |
| SLES 12 SP2 | libXfixes | 5.0.1-7.1 | SUSE-SU-2016:2828-1 |
| SLES 12 SP2 | libXi | 1.7.4-14.1 | SUSE-SU-2016:2828-1 |
| SLES 12 SP2 | libXrender | 0.9.8-7.1 | SUSE-SU-2016:2828-1 |
| SLES 12 SP2 | libXtst | 1.2.2-7.1 | SUSE-SU-2016:2828-1 |
| SLES 12 SP2 | libXv | 1.0.10-7.1 | SUSE-SU-2016:2828-1 |
| SLES 12 SP2 | libXvMC | 1.0.8-7.1 | SUSE-SU-2016:2828-1 |
| SLES 12 SP1 | libX11 | 1.6.2-6.2 | SUSE-SU-2016:2505-1 |
| SLES 12 SP1 | libXfixes | 5.0.1-5.2 | SUSE-SU-2016:2505-1 |
| SLES 12 SP1 | libXi | 1.7.4-12.2 | SUSE-SU-2016:2505-1 |
| SLES 12 SP1 | libXrandr | 1.4.2-5.2 | SUSE-SU-2016:2505-1 |
| SLES 12 SP1 | libXrender | 0.9.8-5.2 | SUSE-SU-2016:2505-1 |
| SLES 12 SP1 | libXtst | 1.2.2-5.2 | SUSE-SU-2016:2505-1 |
| SLES 12 SP1 | libXv | 1.0.10-5.2 | SUSE-SU-2016:2505-1 |
| SLES 12 SP1 | libXvMC | 1.0.8-5.2 | SUSE-SU-2016:2505-1 |
| SLES 11 SP4 | xorg-x11-libs | 7.4-8.26.49.1 | SUSE-SU-2016:3189-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP2 | libX11 | 1.6.2-8.1 | SUSE-SU-2016:2828-1 |
| SLES for SAP 12 SP2 | libXfixes | 5.0.1-7.1 | SUSE-SU-2016:2828-1 |
| SLES for SAP 12 SP2 | libXi | 1.7.4-14.1 | SUSE-SU-2016:2828-1 |
| SLES for SAP 12 SP2 | libXrender | 0.9.8-7.1 | SUSE-SU-2016:2828-1 |
| SLES for SAP 12 SP2 | libXtst | 1.2.2-7.1 | SUSE-SU-2016:2828-1 |
| SLES for SAP 12 SP2 | libXv | 1.0.10-7.1 | SUSE-SU-2016:2828-1 |
| SLES for SAP 12 SP2 | libXvMC | 1.0.8-7.1 | SUSE-SU-2016:2828-1 |
| SLES for SAP 12 SP1 | libX11 | 1.6.2-6.2 | SUSE-SU-2016:2505-1 |
| SLES for SAP 12 SP1 | libXfixes | 5.0.1-5.2 | SUSE-SU-2016:2505-1 |
| SLES for SAP 12 SP1 | libXi | 1.7.4-12.2 | SUSE-SU-2016:2505-1 |
| SLES for SAP 12 SP1 | libXrandr | 1.4.2-5.2 | SUSE-SU-2016:2505-1 |
| SLES for SAP 12 SP1 | libXrender | 0.9.8-5.2 | SUSE-SU-2016:2505-1 |
| SLES for SAP 12 SP1 | libXtst | 1.2.2-5.2 | SUSE-SU-2016:2505-1 |
| SLES for SAP 12 SP1 | libXv | 1.0.10-5.2 | SUSE-SU-2016:2505-1 |
| SLES for SAP 12 SP1 | libXvMC | 1.0.8-5.2 | SUSE-SU-2016:2505-1 |
| SLES for SAP 11 SP4 | xorg-x11-libs | 7.4-8.26.49.1 | SUSE-SU-2016:3189-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.3 | libxtst | 1.2.2-r1 | — |
| Alpine v3.2 | libxtst | 1.2.2-r1 | — |
Advisories 5
- USN-8939-1 libxtst vulnerabilities Ubuntu Security Notices (USN) · Oct 20, 2026
- DLA-686-1 libxtst - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2016:2505-1 Security update for X Window System client libraries SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2828-1 Security update for X Window System client libraries SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3189-1 Security update for xorg-x11-libs SUSE / openSUSE Security Updates · May 2, 2025
References
- 1036945 vdb-entry
- FEDORA-2016-c1d4b1df79 vendor-advisory
- 93375 vdb-entry
- https://cgit.freedesktop.org/xorg/lib/libXtst/commit/?id=9556ad67af3129ec4a7a4f4b54a0d59701beeae3
- [xorg-announce] 20161004 X.Org security advisory: Protocol handling issues in X Window System client libraries mailing-list
- [oss-security] 20161004 Re: X.Org security advisory: Protocol handling issues in X Window System client libraries mailing-list
- FEDORA-2016-e6ba110670 vendor-advisory
- [oss-security] 20161004 X.Org security advisory: Protocol handling issues in X Window System client libraries mailing-list