Use-after-free in Linux kernel - CVE-2026-99039

 

Use-after-free in Linux kernel - CVE-2026-99039

Published: October 23, 2026


Vulnerability identifier: #VU157458
CSH Severity: Low
CVSS v4: 5.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-99039
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to corrupt kernel memory and potentially cause a denial of service.

The vulnerability exists due to use-after-free in the Linux kernel memstick core when device identification or address configuration requests time out while asynchronous processing remains in progress. A local user can trigger request processing that encounters this timeout condition to cause a host controller driver to write into an already freed card structure, potentially crashing the system.


Affected software

Linux kernel
SUSE Linux Micro
SUSE Linux Micro Extras
kernel-default
kernel-64kb
kernel-64kb-debugsource
kernel-64kb-devel
kernel-default-devel
kernel-syms
kernel-obs-build
kernel-obs-build-debugsource
kernel-default-debugsource
kernel-default-devel-debuginfo

How to mitigate CVE-2026-99039

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-default - update to 6.4.0-159998.55.1
kernel-64kb - update to 6.4.0-159998.55.1
kernel-64kb-debugsource - update to 6.4.0-159998.55.1
kernel-64kb-devel - update to 6.4.0-159998.55.1
kernel-default-devel - update to 6.4.0-159998.55.1
kernel-syms - update to 6.4.0-159998.55.1
kernel-obs-build - update to 6.4.0-159998.55.1
kernel-obs-build-debugsource - update to 6.4.0-159998.55.1
kernel-default-debugsource - update to 6.4.0-159998.55.1
kernel-default-devel-debuginfo - update to 6.4.0-159998.55.1

External References

Related Security Bulletins