CVE-2026-88806: x.org libx11 Heap-based Buffer Overflow
CVSS: 7.5v3.1HighAwaiting analysis
AliasesSUSE-SU-2026:23885-1SUSE-SU-2026:23899-1UBUNTU-CVE-2026-88806DEBIAN-CVE-2026-88806openSUSE-SU-2026:11833-1openSUSE-SU-2026:21908-1ALPINE-CVE-2026-88806
Published 21-09-2026Last modified 22-09-2026
Vulnerability summary
CVE-2026-88806 is a high (CVSS 7.5) Heap-based Buffer Overflow vulnerability in x.org libx11. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.1% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
0.20%
0%100%
Low · Change unavailableKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 6 · Related 5Timeline
- 21-09-2026PublishedVulnerability first disclosed.
- 22-09-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 5 sources · 1 versionHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HSourcesAll 5 agree
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.20%
Chance of exploitation in the next 30 days
Percentile
9%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
22-09-202619-10-2026
EPSS score0.20%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Suse3 products
- libX11&distro=SUSE Linux Enterprise Server 16.0< 1.8.10-160000.4.1
- libX11&distro=SUSE Linux Enterprise Server for SAP applications 16.0< 1.8.10-160000.4.1
- libX11&distro=SUSE Linux Micro 6.2< 1.8.10-160000.4.1
Opensuse2 products
- libX11&distro=openSUSE Leap 16.0< 1.8.10-160000.4.1
- libX11&distro=openSUSE Tumbleweed< 1.8.13-2.1
Alpine1 product
- libx11< 1.8.14-r0
Debian1 product
- libx11All versions (No fix recorded)
Ubuntu1 product
- libx11All versions (No fix recorded) | < 2:1.6.2-1ubuntu2.1+esm6 | < 2:1.6.3-1ubuntu2.2+esm5 | < 2:1.6.4-3ubuntu0.4+esm3 | < 2:1.6.9-2ubuntu1.6+esm1 | < 2:1.7.5-1ubuntu0.4 | < 2:1.8.7-1ubuntu0.1 | < 2:1.8.13-1ubuntu0.1
X.org1 product
- libx11< 1.8.14
6 vendors · 9 products
