CVE-2023-43785 — Libx11: out-of-bounds memory access in _xkbreadkeysyms()

Description

A vulnerability was found in libX11 due to a boundary condition within the _XkbReadKeySyms() function. This flaw allows a local user to trigger an out-of-bounds read error and read the contents of memory on the system.

Affected products

Vendor	Product	Affected	Fixed
—	libX11	< 1.8.7	1.8.7
Red Hat	Red Hat Enterprise Linux 8	—	—
Red Hat	Red Hat Enterprise Linux 9	—	—
Red Hat	Red Hat Enterprise Linux 6	—	—
Red Hat	Red Hat Enterprise Linux 7	—	—

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	2:1.8.7-1	—
Debian 13	libx11	2:1.8.7-1	—
Debian 12	libx11	2:1.8.4-2+deb12u2	DSA-5517-1
Debian 11	libx11	2:1.7.2-1+deb11u2	DSA-5517-1
Debian 10	libx11	2:1.6.7-1+deb10u4	DLA-3602-1

Ubuntu

Security tracker ↗

Release	Package	Fixed in	Advisory
Ubuntu 22.04 LTS	libx11	2:1.7.5-1ubuntu0.3	USN-6407-1
Ubuntu 20.04 LTS	libx11	2:1.6.9-2ubuntu1.6	USN-6407-1

Show 3 more (older releases, extended support, other products)

Release	Package	Fixed in	Advisory
Ubuntu Pro 18.04 LTS	libx11	2:1.6.4-3ubuntu0.4+esm2	USN-6407-2
Ubuntu Pro 16.04 LTS	libx11	2:1.6.3-1ubuntu2.2+esm4	USN-6407-2
Ubuntu Pro 14.04 LTS	libx11	2:1.6.2-1ubuntu2.1+esm5	USN-6407-2

Red Hat

Security tracker ↗

Release	Package	Fixed in	Advisory
RHEL 9	libX11 +3	1.7.0-9.el9	RHSA-2024:2145
RHEL 8	libX11 +3	1.6.8-8.el8	RHSA-2024:2973

AlmaLinux

Errata ↗

Release	Package	Fixed in	Advisory
AlmaLinux 9	libX11 +3	1.7.0-9.el9	ALSA-2024:2145
AlmaLinux 8	libX11 +3	1.6.8-8.el8	ALSA-2024:2973

Rocky Linux

Errata ↗

Release	Package	Fixed in	Advisory
Rocky Linux 9	libX11	1.7.0-9.el9	RLSA-2024:2145
Rocky Linux 8	libX11	1.6.8-8.el8	RLSA-2024:2973

SUSE

Security tracker ↗

Release	Package	Fixed in	Advisory
SLES 15 SP5	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1
SLES 15 SP4	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1
SLES 12 SP5	libX11	1.6.2-12.33.1	SUSE-SU-2023:3989-1

Show 7 more (older releases, extended support, other products)

Release	Package	Fixed in	Advisory
SLES for SAP 12 SP5	libX11	1.6.2-12.33.1	SUSE-SU-2023:3989-1
SLE Micro 5.5	libX11	1.6.5-150000.3.33.1	SUSE-SU-2024:2453-1, SUSE-SU-2023:3963-1
SLE Micro 5.4	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1
SLE Micro 5.3	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1
SLE Micro 5.2	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1
SUSE Manager Server 4.2	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1
SUSE Manager Proxy 4.2	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1

openSUSE

Security tracker ↗

Release	Package	Fixed in	Advisory
openSUSE Leap 15.5	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1
openSUSE Leap 15.4	libX11	1.6.5-150000.3.33.1	SUSE-SU-2023:3963-1

Alpine

Security tracker ↗

Release	Package	Fixed in	Advisory
Alpine v3.24	libx11	1.8.7-r0	—
Alpine v3.23	libx11	1.8.7-r0	—
Alpine v3.22	libx11	1.8.7-r0	—
Alpine v3.21	libx11	1.8.7-r0	—
Alpine v3.20	libx11	1.8.7-r0	—

Show 4 more (older releases, extended support, other products)

Release	Package	Fixed in	Advisory
Alpine v3.19	libx11	1.8.7-r0	—
Alpine v3.18	libx11	1.8.7-r0	—
Alpine v3.17	libx11	1.8.7-r0	—
Alpine v3.16	libx11	1.8.7-r0	—

Amazon Linux

Release	Package	Fixed in	Advisory
Amazon Linux 2023	libX11 +3	1.7.2-3.amzn2023.0.4	ALAS2023-2023-383
Amazon Linux 2	libX11 +2	1.6.7-3.amzn2.0.4	ALAS2-2023-2296

Azure Linux

Release	Package	Fixed in	Advisory
Azure Linux 2 (CBL-Mariner)	libX11	1.8.7-1	—

Oracle Linux

Release	Package	Fixed in	Advisory
Oracle Linux 9	libX11 +3	1.7.0-9.el9	ELSA-2024-2145
Oracle Linux 8	libX11 +3	1.6.8-8.el8	ELSA-2024-2973

Advisories 20

ALSA-2024:2145 Moderate: libX11 security update AlmaLinux Security Advisories · Oct 29, 2026
ALSA-2024:2973 Moderate: libX11 security update AlmaLinux Security Advisories · Oct 29, 2026
USN-6407-2 libx11 vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
WID-SEC-2024-1226 Red Hat OpenShift: Mehrere Schwachstellen BSI CERT-Bund (WID) · May 11, 2026
USN-6407-1 libx11 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
RHSA-2024:2973 Red Hat Security Advisory: libX11 security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
RHSA-2024:2145 Red Hat Security Advisory: libX11 security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
DSA-5517-1 libx11 - security update Debian Security (DSA / DLA) · Mar 9, 2026
DLA-3602-1 libx11 - security update Debian Security (DSA / DLA) · Mar 9, 2026
SUSE-SU-2023:3989-1 Security update for libX11 SUSE / openSUSE Security Updates · Feb 4, 2026
SUSE-SU-2023:3963-1 Security update for libX11 SUSE / openSUSE Security Updates · Feb 4, 2026
SUSE-SU-2024:2453-1 Security update for libX11 SUSE / openSUSE Security Updates · Feb 4, 2026
WID-SEC-2023-2544 X.Org X11: Mehrere Schwachstellen BSI CERT-Bund (WID) · May 7, 2025
RLSA-2024:2145 Moderate: libX11 security update Rocky Linux Security Advisories · May 7, 2025
RLSA-2024:2973 Moderate: libX11 security update Rocky Linux Security Advisories · May 7, 2025
WID-SEC-2024-1248 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 21, 2024
ELSA-2024-2973 Moderate: libX11 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 23, 2024
ELSA-2024-2145 Moderate: libX11 security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · May 2, 2024
ALAS2023-2023-383 Moderate: libX11 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 24, 2023
ALAS2-2023-2296 Moderate: libX11 security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Oct 19, 2023

References

RHSA-2024:2145 vendor-advisory
RHSA-2024:2973 vendor-advisory
https://access.redhat.com/security/cve/CVE-2023-43785 vdb-entry
RHBZ#2242252 issue-tracking

CNA	v3.1	6.5
EUVD	v3.1	6.5