Use-after-free in Linux kernel - CVE-2026-74637
Published: August 24, 2026
Vulnerability identifier: #VU144931
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-2026-74637
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in perf/core group handling when processing a PERF_IOC_FLAG_GROUP ioctl on a detached sibling event after CPU hotplug detachment. A local user can issue a crafted ioctl on a surviving perf event file descriptor to cause a denial of service.
The issue occurs when a sibling event is detached with DETACH_GROUP and kept alive while its group_leader pointer still references a leader that is later freed.
Affected software
Linux kernel
Debian Linux
linux (Debian package)
Debian Linux
linux (Debian package)
How to mitigate CVE-2026-74637
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Debian package) - update to 6.12.105-1
linux (Debian package) - update to 6.12.105-1