CVE-2026-34002Xorg: xwayland: x.org x server: information disclosure or denial of service via out-of-bounds read in xkb modifier map handling

Description

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.

Timeline

Scores

EPSS (exploitation in 30 days)

0.49% · top 57% of all CVEs (13 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.1.

Affected products

• Red Hat · Red Hat Enterprise Linux 10.0 Extended Update Support

  • unaffected 0:24.1.5-6.el10_0 – < *

• Red Hat · Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION

  • unaffected 0:1.1.0-25.el6_10.16 – < *

• Red Hat · Red Hat Enterprise Linux 7 Extended Lifecycle Support

  • unaffected 0:1.20.4-34.el7_9 – < *

• Red Hat · Red Hat Enterprise Linux 7 Extended Lifecycle Support

  • unaffected 0:1.8.0-36.el7_9.4 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

  • unaffected 0:1.20.10-4.el8_4 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

  • unaffected 0:1.11.0-8.el8_4.15 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

  • unaffected 0:1.20.10-4.el8_4 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

  • unaffected 0:1.11.0-8.el8_4.15 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

  • unaffected 0:21.1.3-2.el8_6.6 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

  • unaffected 0:1.20.11-7.el8_6 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

  • unaffected 0:1.12.0-6.el8_6.17 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

  • unaffected 0:1.12.0-6.el8_6.17 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Telecommunications Update Service

  • unaffected 0:21.1.3-2.el8_6.6 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Telecommunications Update Service

  • unaffected 0:1.20.11-7.el8_6 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions

  • unaffected 0:21.1.3-2.el8_6.6 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions

  • unaffected 0:1.20.11-7.el8_6 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service

  • unaffected 0:21.1.3-13.el8_8 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service

  • unaffected 0:1.20.11-18.el8_8 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service

  • unaffected 0:1.12.0-15.el8_8.17 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

  • unaffected 0:21.1.3-13.el8_8 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

  • unaffected 0:1.20.11-18.el8_8 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

  • unaffected 0:1.12.0-15.el8_8.17 – < *

• Red Hat · Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

  • unaffected 0:21.1.3-5.el9_0 – < *

• Red Hat · Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

  • unaffected 0:1.20.11-13.el9_0 – < *

• Red Hat · Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

  • unaffected 0:1.11.0-22.el9_0.17 – < *

• Red Hat · Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

  • unaffected 0:21.1.3-10.el9_2 – < *

• Red Hat · Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

  • unaffected 0:1.20.11-20.el9_2 – < *

• Red Hat · Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

  • unaffected 0:1.12.0-14.el9_2.14 – < *

• Red Hat · Red Hat Enterprise Linux 9.4 Extended Update Support

  • unaffected 0:1.20.11-28.el9_4 – < *

• Red Hat · Red Hat Enterprise Linux 9.4 Extended Update Support

  • unaffected 0:22.1.9-8.el9_4 – < *

• Red Hat · Red Hat Enterprise Linux 9.4 Extended Update Support

  • unaffected 0:1.13.1-8.el9_4.9 – < *

• Red Hat · Red Hat Enterprise Linux 9.6 Extended Update Support

  • unaffected 0:1.20.11-33.el9_6 – < *

• Red Hat · Red Hat Enterprise Linux 9.6 Extended Update Support

  • unaffected 0:23.2.7-6.el9_6 – < *

• Red Hat · Red Hat Enterprise Linux 9.6 Extended Update Support

  • unaffected 0:1.14.1-10.el9_6 – < *

• Red Hat · Red Hat Enterprise Linux 10

  All versions: affected

• Red Hat · Red Hat Enterprise Linux 6

  All versions: unknown

• Red Hat · Red Hat Enterprise Linux 8

  All versions: affected

• Red Hat · Red Hat Enterprise Linux 8

  All versions: affected

• Red Hat · Red Hat Enterprise Linux 8

  All versions: affected

• Red Hat · Red Hat Enterprise Linux 9

  All versions: affected

• Red Hat · Red Hat Enterprise Linux 9

  All versions: affected

• Red Hat · Red Hat Enterprise Linux 9

  All versions: affected

What to do

Workaround: To mitigate this vulnerability, restrict access to the X11 server. If the X.Org X server is not required on a system, consider disabling or uninstalling it. For systems where the X server is necessary, ensure that access is limited to trusted users and networks. This can involve configuring `xhost` or implementing firewall rules to restrict connections to the X server. Any changes to X server configuration or service status may require a restart of the X server for the mitigation to take effect, which will impact active graphical sessions.

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-27343 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-34002](https://cveledger.app/badge/CVE-2026-34002.svg)](https://cveledger.app/cve/CVE-2026-34002)

Record last updated 5 Nov 2026, 20:29 UTC.