Vulnerability in X.org X Server
CVE-2026-34002
A flaw was found in the X.Org X server. This vulnerability, an out-of-bounds read, affects the XKB (X Keyboard Extension) modifier map handling. An attacker with access to the X11 server can exploit this by sending a malformed request, which causes the server to read beyond its intended memory boundaries. This can lead to the exposure of sensitive information or cause the server to crash, resulting in a denial of service.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (43.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 43.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000
Affected products
- X.org X Server
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 10.0 Extended Update Support — versions 0:24.1.5-6.el10_0
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 6 Extended Lifecycle Support - Extension — versions 0:1.1.0-25.el6_10.16
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 7 Extended Lifecycle Support — versions 0:1.20.4-34.el7_9, 0:1.8.0-36.el7_9.4
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support — versions 0:1.11.0-8.el8_4.15, 0:1.20.10-4.el8_4
- Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On — versions 0:1.11.0-8.el8_4.15, 0:1.20.10-4.el8_4
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-34002 (Third Party Advisory, vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Third Party Advisory, Issue Tracking)
- access.redhat.com/errata/RHSA-2026:20562 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:20560 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:20558 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:20561 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:20563 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:20575 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:20590 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:20555 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-34002?
- CVE-2026-34002 is a medium-severity vulnerability in X.org X Server, classified under Buffer Access with Incorrect Length Value. CVSS score: 6.1/10. Published 2026-05-05.
- How severe is CVE-2026-34002?
- Medium severity. CVSS v3 base score is 6.1 out of 10.