Description
An out-of-bounds read in libX11's byte-oriented codeset parser in libX11 before 1.8.14 could be used by malicious X servers to crash attached X clients.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| x.org | libX11 | < 1.8.14 | 1.8.14 |
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 | libx11 | 2:1.8.14-1 | — |
| Debian 13 | libx11 | No fix yet | — |
| Debian 12 | libx11 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libx11 | No fix yet | — |
| Ubuntu 26.04 LTS | libx11 | 2:1.8.13-1ubuntu0.1 | USN-8913-1 |
| Ubuntu 24.04 LTS | libx11 | 2:1.8.7-1ubuntu0.1 | USN-8913-1 |
| Ubuntu 22.04 LTS | libx11 | 2:1.7.5-1ubuntu0.4 | USN-8913-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | libx11 | 2:1.6.9-2ubuntu1.6+esm1 | USN-8913-1 |
| Ubuntu Pro 18.04 LTS | libx11 | 2:1.6.4-3ubuntu0.4+esm3 | USN-8913-1 |
| Ubuntu Pro 16.04 LTS | libx11 | 2:1.6.3-1ubuntu2.2+esm5 | USN-8913-1 |
| Ubuntu Pro 14.04 LTS | libx11 | 2:1.6.2-1ubuntu2.1+esm6 | USN-8913-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | libX11 +3 | 1.8.13-3.1.hum1 | RHSA-2026:79278 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | libX11 | 1.8.10-150700.4.8.1 | SUSE-SU-2026:4502-1 |
| SLES 15 SP6 | libX11 | 1.8.7-150600.3.11.1 | SUSE-SU-2026:4501-1 |
| SLES 15 SP5 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
| SLES 15 SP4 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
| SLES 12 SP5 | libX11 | 1.6.2-12.41.1 | SUSE-SU-2026:4410-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | libX11 | 1.8.10-160000.5.1 | SUSE-SU-2026:24201-1 |
| SLES for SAP 15 SP6 | libX11 | 1.8.7-150600.3.11.1 | SUSE-SU-2026:4501-1 |
| SLES for SAP 15 SP5 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
| SLES for SAP 15 SP4 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
| SLES 16.0 | libX11 | 1.8.10-160000.5.1 | SUSE-SU-2026:24201-1 |
| SLE Micro 6.2 | libX11 | 1.8.10-160000.5.1 | SUSE-SU-2026:24118-1 |
| SLE Micro 6.1 | libX11 | 1.8.7-slfo.1.1_4.1 | SUSE-SU-2026:24552-1 |
| SLE Micro 6.0 | libX11 | 1.8.7-159998.1.1 | SUSE-SU-2026:24365-1 |
| SLE Micro 5.5 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
| SLE Micro 5.4 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
| SLE Micro 5.3 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
| SLE HPC 15 SP5 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
| SLE HPC 15 SP4 | libX11 | 1.6.5-150000.3.41.1 | SUSE-SU-2026:4500-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libX11 | 1.8.13-3.1 | openSUSE-SU-2026:11894-1 |
| openSUSE Leap 16.0 | libX11 | 1.8.10-160000.5.1 | openSUSE-SU-2026:22055-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | libx11 | 1.8.14-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libX11 | 1.8.14-1 | — |
Advisories 13
- SUSE-SU-2026:24552-1 Security update for libX11 SUSE / openSUSE Security Updates · Nov 7, 2026
- WID-SEC-2026-3606 X.Org X11: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 4, 2026
- SUSE-SU-2026:24365-1 Security update for libX11 SUSE / openSUSE Security Updates · Oct 27, 2026
- SUSE-SU-2026:24201-1 Security update for libX11 SUSE / openSUSE Security Updates · Oct 21, 2026
- openSUSE-SU-2026:22055-1 Security update for libX11 SUSE / openSUSE Security Updates · Oct 19, 2026
- SUSE-SU-2026:24118-1 Security update for libX11 SUSE / openSUSE Security Updates · Oct 13, 2026
- USN-8913-1 libx11 vulnerabilities Ubuntu Security Notices (USN) · Oct 12, 2026
- RHSA-2026:79278 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- SUSE-SU-2026:4500-1 Security update for libX11 SUSE / openSUSE Security Updates · Oct 6, 2026
- SUSE-SU-2026:4501-1 Security update for libX11 SUSE / openSUSE Security Updates · Oct 6, 2026
- SUSE-SU-2026:4502-1 Security update for libX11 SUSE / openSUSE Security Updates · Oct 6, 2026
- SUSE-SU-2026:4410-1 Security update for libX11 SUSE / openSUSE Security Updates · Oct 2, 2026
- openSUSE-SU-2026:11894-1 libX11-6-1.8.13-3.1 on GA media SUSE / openSUSE Security Updates · Sep 29, 2026