CVE Vulnerabilities

CVE-2026-34001

Expired Pointer Dereference

Published: Apr 23, 2026 | Modified: Jun 08, 2026
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
7.8 IMPORTANT
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM
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A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence() function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially enabling memory corruption. This could result in a denial of service or further compromise of the system.

Weakness

The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.

Affected Software

NameVendorStart VersionEnd Version
Red Hat Enterprise Linux 10RedHatxorg-x11-server-Xwayland-0:24.1.5-6.el10_1*
Red Hat Enterprise Linux 10RedHatxorg-x11-server-Xwayland-0:24.1.9-4.el10_2*
Red Hat Enterprise Linux 10.0 Extended Update SupportRedHatxorg-x11-server-Xwayland-0:24.1.5-6.el10_0*
Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSIONRedHattigervnc-0:1.1.0-25.el6_10.16*
Red Hat Enterprise Linux 7 Extended Lifecycle SupportRedHatxorg-x11-server-0:1.20.4-34.el7_9*
Red Hat Enterprise Linux 7 Extended Lifecycle SupportRedHattigervnc-0:1.8.0-36.el7_9.4*
Red Hat Enterprise Linux 8RedHatxorg-x11-server-Xwayland-0:21.1.3-20.el8_10*
Red Hat Enterprise Linux 8RedHatxorg-x11-server-0:1.20.11-28.el8_10*
Red Hat Enterprise Linux 8RedHattigervnc-0:1.15.0-9.el8_10*
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportRedHatxorg-x11-server-0:1.20.10-4.el8_4*
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportRedHattigervnc-0:1.11.0-8.el8_4.15*
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-OnRedHatxorg-x11-server-0:1.20.10-4.el8_4*
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-OnRedHattigervnc-0:1.11.0-8.el8_4.15*
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRedHatxorg-x11-server-Xwayland-0:21.1.3-2.el8_6.6*
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRedHatxorg-x11-server-0:1.20.11-7.el8_6*
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRedHattigervnc-0:1.12.0-6.el8_6.17*
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnRedHattigervnc-0:1.12.0-6.el8_6.17*
Red Hat Enterprise Linux 8.6 Telecommunications Update ServiceRedHatxorg-x11-server-Xwayland-0:21.1.3-2.el8_6.6*
Red Hat Enterprise Linux 8.6 Telecommunications Update ServiceRedHatxorg-x11-server-0:1.20.11-7.el8_6*
Red Hat Enterprise Linux 8.6 Update Services for SAP SolutionsRedHatxorg-x11-server-Xwayland-0:21.1.3-2.el8_6.6*
Red Hat Enterprise Linux 8.6 Update Services for SAP SolutionsRedHatxorg-x11-server-0:1.20.11-7.el8_6*
Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceRedHatxorg-x11-server-Xwayland-0:21.1.3-13.el8_8*
Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceRedHatxorg-x11-server-0:1.20.11-18.el8_8*
Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceRedHattigervnc-0:1.12.0-15.el8_8.17*
Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsRedHatxorg-x11-server-Xwayland-0:21.1.3-13.el8_8*
Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsRedHatxorg-x11-server-0:1.20.11-18.el8_8*
Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsRedHattigervnc-0:1.12.0-15.el8_8.17*
Red Hat Enterprise Linux 9RedHattigervnc-0:1.15.0-6.el9_7.1*
Red Hat Enterprise Linux 9RedHatxorg-x11-server-Xwayland-0:23.2.7-6.el9_7*
Red Hat Enterprise Linux 9RedHatxorg-x11-server-0:1.20.11-33.el9_7*
Red Hat Enterprise Linux 9RedHattigervnc-0:1.15.0-7.el9_8.1*
Red Hat Enterprise Linux 9RedHatxorg-x11-server-0:1.20.11-34.el9_8*
Red Hat Enterprise Linux 9RedHatxorg-x11-server-Xwayland-0:24.1.9-4.el9_8*
Red Hat Enterprise Linux 9.0 Update Services for SAP SolutionsRedHatxorg-x11-server-Xwayland-0:21.1.3-5.el9_0*
Red Hat Enterprise Linux 9.0 Update Services for SAP SolutionsRedHatxorg-x11-server-0:1.20.11-13.el9_0*
Red Hat Enterprise Linux 9.0 Update Services for SAP SolutionsRedHattigervnc-0:1.11.0-22.el9_0.17*
Red Hat Enterprise Linux 9.2 Update Services for SAP SolutionsRedHatxorg-x11-server-Xwayland-0:21.1.3-10.el9_2*
Red Hat Enterprise Linux 9.2 Update Services for SAP SolutionsRedHatxorg-x11-server-0:1.20.11-20.el9_2*
Red Hat Enterprise Linux 9.2 Update Services for SAP SolutionsRedHattigervnc-0:1.12.0-14.el9_2.14*
Red Hat Enterprise Linux 9.4 Extended Update SupportRedHatxorg-x11-server-0:1.20.11-28.el9_4*
Red Hat Enterprise Linux 9.4 Extended Update SupportRedHatxorg-x11-server-Xwayland-0:22.1.9-8.el9_4*
Red Hat Enterprise Linux 9.4 Extended Update SupportRedHattigervnc-0:1.13.1-8.el9_4.9*
Red Hat Enterprise Linux 9.6 Extended Update SupportRedHatxorg-x11-server-0:1.20.11-33.el9_6*
Red Hat Enterprise Linux 9.6 Extended Update SupportRedHatxorg-x11-server-Xwayland-0:23.2.7-6.el9_6*
Red Hat Enterprise Linux 9.6 Extended Update SupportRedHattigervnc-0:1.14.1-10.el9_6*
Xorg-serverUbuntuesm-infra/xenial*
Xorg-serverUbuntuupstream*
Xorg-server-hwe-16.04Ubuntuesm-infra/xenial*
XwaylandUbuntuupstream*

Potential Mitigations

References