Vulnerability · Published Sep 21, 2026 · Assigned by suse
CVE-2026-88806libX11 XkbGetMap Reply Heap-based Buffer Overflow
High 7.5
In plain English
A high-severity heap buffer overflow in libX11 from x.org. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.2%top 89.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | libX11 | 1.8.10-1.el10_2.1 | ALSA-2026:91366 |
| AlmaLinux:8 | libX11 | 1.6.8-10.el8_10 | ALSA-2026:89730 |
| AlmaLinux:9 | libX11 | 1.8.12-1.el9_8.1 | ALSA-2026:91365 |
| AlmaLinux:10 | libX11-common | 1.8.10-1.el10_2.1 | ALSA-2026:91366 |
| AlmaLinux:8 | libX11-common | 1.6.8-10.el8_10 | ALSA-2026:89730 |
| AlmaLinux:9 | libX11-common | 1.8.12-1.el9_8.1 | ALSA-2026:91365 |
| AlmaLinux:10 | libX11-devel | 1.8.10-1.el10_2.1 | ALSA-2026:91366 |
| AlmaLinux:8 | libX11-devel | 1.6.8-10.el8_10 | ALSA-2026:89730 |
| AlmaLinux:9 | libX11-devel | 1.8.12-1.el9_8.1 | ALSA-2026:91365 |
| AlmaLinux:10 | libX11-xcb | 1.8.10-1.el10_2.1 | ALSA-2026:91366 |
| AlmaLinux:8 | libX11-xcb | 1.6.8-10.el8_10 | ALSA-2026:89730 |
| AlmaLinux:9 | libX11-xcb | 1.8.12-1.el9_8.1 | ALSA-2026:91365 |
| Alpine:v3.24 | libx11 | 1.8.14-r0 | ALPINE-CVE-2026-88806 |
| Debian:12 | libx11 | no fix listed | DEBIAN-CVE-2026-88806 |
| Debian:13 | libx11 | no fix listed | DEBIAN-CVE-2026-88806 |
| Debian:14 | libx11 | 2:1.8.14-1 | DEBIAN-CVE-2026-88806 |
| Rocky Linux:10 | libX11 | 0:1.8.10-1.el10_2.1 | RLSA-2026:91366 |
| Rocky Linux:8 | libX11 | 0:1.6.8-10.el8_10 | RLSA-2026:89730 |
| Rocky Linux:9 | libX11 | 0:1.8.12-1.el9_8.1 | RLSA-2026:91365 |
| Ubuntu:22.04:LTS | libx11 | 2:1.7.5-1ubuntu0.4 | UBUNTU-CVE-2026-88806 |
| Ubuntu:22.04:LTS | libx11 | 2:1.7.5-1ubuntu0.4 | USN-8913-1 |
| Ubuntu:24.04:LTS | libx11 | 2:1.8.7-1ubuntu0.1 | UBUNTU-CVE-2026-88806 |
| Ubuntu:24.04:LTS | libx11 | 2:1.8.7-1ubuntu0.1 | USN-8913-1 |
| Ubuntu:26.04:LTS | libx11 | 2:1.8.13-1ubuntu0.1 | USN-8913-1 |
| Ubuntu:26.04:LTS | libx11 | 2:1.8.13-1ubuntu0.1 | UBUNTU-CVE-2026-88806 |
| Ubuntu:26.10 | libx11 | no fix listed | UBUNTU-CVE-2026-88806 |
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H