Description
A vulnerability was found in libX11. The security flaw occurs because the functions in src/InitExt.c in libX11 do not check that the values provided for the Request, Event, or Error IDs are within the bounds of the arrays that those functions write to, using those IDs as array indexes. They trust that they were called with values provided by an Xserver adhering to the bounds specified in the X11 protocol, as all X servers provided by X.Org do. As the protocol only specifies a single byte for these values, an out-of-bounds value provided by a malicious server (or a malicious proxy-in-the-middle) can only overwrite other portions of the Display structure and not write outside the bounds of the Display structure itself, possibly causing the client to crash with this memory corruption.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | libX11 | libX11 1.8.6 | — |
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 | 2:1.8.6-1 | — |
| Debian 13 | libx11 | 2:1.8.6-1 | — |
| Debian 12 | libx11 | 2:1.8.4-2+deb12u1 | DSA-5433-1 |
| Debian 11 | libx11 | 2:1.7.2-1+deb11u1 | DSA-5433-1 |
| Debian 10 | libx11 | 2:1.6.7-1+deb10u3 | DLA-3472-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | libx11 | 2:1.7.5-1ubuntu0.2 | USN-6168-1 |
| Ubuntu 20.04 LTS | libx11 | 2:1.6.9-2ubuntu1.5 | USN-6168-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | libx11 | 2:1.6.4-3ubuntu0.4+esm1 | USN-6168-2 |
| Ubuntu Pro 16.04 LTS | libx11 | 2:1.6.3-1ubuntu2.2+esm2 | USN-6168-2 |
| Ubuntu Pro 14.04 LTS | libx11 | 2:1.6.2-1ubuntu2.1+esm3 | USN-6168-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | libX11 +3 | 1.7.0-8.el9 | RHSA-2023:6497 |
| RHEL 8 | libX11 +3 | 1.6.8-6.el8 | RHSA-2023:7029 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.2 EUS | libX11 +3 | 1.7.0-8.el9_2 | RHSA-2024:1088 |
| RHEL 8.8 EUS | libX11 +3 | 1.6.8-6.el8_8 | RHSA-2024:1417 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | libX11 +3 | 1.7.0-8.el9 | ALSA-2023:6497 |
| AlmaLinux 8 | libX11 +3 | 1.6.8-6.el8 | ALSA-2023:7029 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLES 15 SP4 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLES 15 SP3 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLES 15 SP2 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLES 15 SP1 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
Show 21 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | libX11 | 1.6.2-12.30.1 | SUSE-SU-2023:2531-1 |
| SLES 12 SP4 | libX11 | 1.6.2-12.30.1 | SUSE-SU-2023:2531-1 |
| SLES 12 SP2 | libX11 | 1.6.2-12.30.1 | SUSE-SU-2023:2531-1 |
| SLES for SAP 15 SP3 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLES for SAP 15 SP2 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLES for SAP 15 SP1 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLES for SAP 12 SP5 | libX11 | 1.6.2-12.30.1 | SUSE-SU-2023:2531-1 |
| SLES for SAP 12 SP4 | libX11 | 1.6.2-12.30.1 | SUSE-SU-2023:2531-1 |
| SLE Real Time 15 SP3 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLE Micro 5.4 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLE Micro 5.3 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLE Micro 5.2 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLE HPC 15 SP3 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLE HPC 15 SP2 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SLE HPC 15 SP1 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SUSE OpenStack Cloud Crowbar 9 | libX11 | 1.6.2-12.30.1 | SUSE-SU-2023:2531-1 |
| SUSE OpenStack Cloud 9 | libX11 | 1.6.2-12.30.1 | SUSE-SU-2023:2531-1 |
| SUSE Manager Server 4.2 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SUSE Manager Proxy 4.2 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SUSE Enterprise Storage 7.1 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| SUSE Enterprise Storage 7 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.5 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
| openSUSE Leap 15.4 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap Micro 5.3 | libX11 | 1.6.5-150000.3.30.1 | SUSE-SU-2023:2614-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.18 | libx11 | 1.8.4-r4 | — |
| Alpine v3.17 | libx11 | 1.8.4-r1 | — |
| Alpine v3.16 | libx11 | 1.8-r1 | — |
| Alpine v3.15 | libx11 | 1.7.3.1-r1 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | libX11 +3 | 1.7.2-3.amzn2023.0.3 | ALAS2023-2023-250 |
| Amazon Linux 2 | libX11 +2 | 1.6.7-3.amzn2.0.3 | ALAS2-2023-2129 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | libX11 | 1.6.12-6 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | libX11 +3 | 1.7.0-8.el9 | ELSA-2023-6497 |
| Oracle Linux 8 | libX11 +3 | 1.6.8-6.el8 | ELSA-2023-7029 |
Advisories 20
- ALSA-2023:6497 Moderate: libX11 security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2023:7029 Moderate: libX11 security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2024-0794 Dell ECS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 11, 2026
- WID-SEC-2023-2917 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 30, 2026
- USN-6168-2 libx11 vulnerability Ubuntu Security Notices (USN) · Jun 29, 2026
- USN-6168-1 libx11 vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- RHSA-2024:1417 Red Hat Security Advisory: libX11 security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2024:1088 Red Hat Security Advisory: libX11 security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- DSA-5433-1 libx11 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3472-1 libx11 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2023:2614-1 Security update for libX11 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:2531-1 Security update for libX11 SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2023:7029 Red Hat Security Advisory: libX11 security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2023:6497 Red Hat Security Advisory: libX11 security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- WID-SEC-2023-1485 X.Org X11: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Nov 6, 2025
- WID-SEC-2024-1086 IBM QRadar SIEM: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 19, 2025
- ELSA-2023-7029 Moderate: libX11 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 17, 2023
- ELSA-2023-6497 Moderate: libX11 security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Nov 11, 2023
- ALAS2023-2023-250 Moderate: libX11 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 20, 2023
- ALAS2-2023-2129 Moderate: libX11 security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 19, 2023
References
- https://access.redhat.com/security/cve/CVE-2023-3138
- https://gitlab.freedesktop.org/xorg/lib/libx11/-/commit/304a654a0d57bf0f00d8998185f0360332cfa36c
- https://lists.x.org/archives/xorg-announce/2023-June/003406.html
- https://lists.x.org/archives/xorg-announce/2023-June/003407.html
- https://security.netapp.com/advisory/ntap-20231208-0008/