Use-after-free in Linux kernel - CVE-2026-99218
Published: November 3, 2026
Vulnerability identifier: #VU158740
CSH Severity: Low
CVSS v4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-99218
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 and potentially execute arbitrary code in kernel context or disclose sensitive information.
The vulnerability exists due to use-after-free in the Linux kernel's coredump_finish() function when releasing parked threads without holding a task reference or read-copy-update (RCU) protection. A local user can trigger a race during core dump completion in which a released thread exits and its task structure is freed before wake_up_process() accesses it, causing access to freed kernel memory and potentially enabling code execution, information disclosure, or a system crash.
Affected software
Linux kernel
How to mitigate CVE-2026-99218
Install security update from vendor's repository.
External References
- https://git.kernel.org/stable/c/0fce73efee40c65ce26641c5d93942462f9e8307
- https://git.kernel.org/stable/c/16e94ed90b1b02398e044d41fd1db34828daa08e
- https://git.kernel.org/stable/c/71146c437bae59e5280f657965dc6d006ee3989b
- https://git.kernel.org/stable/c/a0f09ff4c6b93312e565cfe75d76c3a551a3ec4c
- https://git.kernel.org/stable/c/b0eca0edddf4c1dbaf6d1f6a8636b4235f5bc573
- https://git.kernel.org/stable/c/fd0fbe84312fda2fc187428c92c50b7d03a9d24c