Race condition in Xen - CVE-2026-62432
Published: July 29, 2026
Vulnerability identifier: #VU140015
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-62432
CWE-ID: CWE-362
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local attacker to cause a denial of service.
The vulnerability exists due to a race condition in the EVTCHNOP_expand_array hypercall when checking whether FIFO event channels are enabled without holding the correct lock. A local attacker can trigger EVTCHNOP_expand_array to race with EVTCHNOP_reset to cause a denial of service.
The issue affects malicious guest contexts, including HVM guests on x86 or ARM and PVH guests; x86 PV guests may also be able to trigger memory corruption or privilege escalation.
Affected software
Xen
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
Debian Linux
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Micro
SUSE Linux Enterprise Micro for Rancher
Basesystem Module
Server Applications Module
openSUSE Leap
Fedora
Citrix XenServer
xen-debugsource
xen-tools-domU
xen-libs
xen-devel
xen-libs-debuginfo-32bit
xen-libs-debuginfo
xen-libs-32bit
xen-tools-domU-debuginfo
xen-tools-debuginfo
xen-tools
xen-doc-html
xen
xen-libs-32bit-debuginfo
xen-tools-xendomains-wait-disk
xen (Debian package)
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
Debian Linux
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Micro
SUSE Linux Enterprise Micro for Rancher
Basesystem Module
Server Applications Module
openSUSE Leap
Fedora
Citrix XenServer
xen-debugsource
xen-tools-domU
xen-libs
xen-devel
xen-libs-debuginfo-32bit
xen-libs-debuginfo
xen-libs-32bit
xen-tools-domU-debuginfo
xen-tools-debuginfo
xen-tools
xen-doc-html
xen
xen-libs-32bit-debuginfo
xen-tools-xendomains-wait-disk
xen (Debian package)
How to mitigate CVE-2026-62432
Install security update from vendor's website.
xen-debugsource - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-tools-domU - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-libs - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-devel - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-libs-debuginfo-32bit - update to 4.12.4_72-3.148.4
xen-libs-debuginfo - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-libs-32bit - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3
xen-tools-domU-debuginfo - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-tools-debuginfo - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-tools - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-doc-html - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3
xen - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-libs-32bit-debuginfo - addressed in versions 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3
xen-tools-xendomains-wait-disk - addressed in versions 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen (Debian package) - update to 4.20.3+127-gc42374a105-0+deb13u1
xen - addressed in versions 4.20.4-1.fc43, 4.21.2-1.fc44
xen-tools-domU - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-libs - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-devel - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-libs-debuginfo-32bit - update to 4.12.4_72-3.148.4
xen-libs-debuginfo - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-libs-32bit - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3
xen-tools-domU-debuginfo - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-tools-debuginfo - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-tools - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-doc-html - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3
xen - addressed in versions 4.12.4_72-3.148.4, 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen-libs-32bit-debuginfo - addressed in versions 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3
xen-tools-xendomains-wait-disk - addressed in versions 4.16.7_12-150400.4.89.3, 4.17.6_14-150500.3.76.3, 4.18.5_20-150600.3.53.3, 4.20.4_04-150700.3.46.1
xen (Debian package) - update to 4.20.3+127-gc42374a105-0+deb13u1
xen - addressed in versions 4.20.4-1.fc43, 4.21.2-1.fc44