CVE-2026-34003: xorg-server Out-of-bounds Read
Vulnerability summary
CVE-2026-34003 is a high (CVSS 7.8) Out-of-bounds Read vulnerability in xorg-server. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 7.7% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 48 · Related 12Timeline
- 23-04-2026PublishedVulnerability first disclosed.
- 15-07-2026Last modifiedVulnerability information updated.
Description
A flaw was found in the X.Org X server's XKB key types request validation. A local attacker could send a specially crafted request to the X server, leading to an out-of-bounds memory access vulnerability. This could result in the disclosure of sensitive information or cause the server to crash, leading to a Denial of Service (DoS). In certain configurations, higher impact outcomes may be possible.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
-0.06 pp
From 0.25% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu4 products
- xorg-serverAll versions (No fix recorded)
- xorg-server-hwe-16.04All versions (No fix recorded)
- xorg-server-hwe-18.04All versions (No fix recorded)
- xwaylandAll versions (No fix recorded)
Debian2 products
- xorg-server< 2:21.1.7-3+deb12u12 | < 2:21.1.16-1.3+deb13u2 | < 2:21.1.22-1
- xwaylandAll versions (No fix recorded) | < 2:24.1.10-1
2 vendors · 6 products
