Use-after-free in Linux kernel - CVE-2026-80688

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to use-after-free in vec_check_unaligned_access_speed_all_cpus when executing a kernel thread after the .init.text section has been unmapped during boot completion. A local user can trigger the vulnerable code path to cause a denial of service.

The issue can result in an instruction page fault in the kernel if the asynchronous probing operation is still running when free_initmem() unmaps the freed region.

Affected software

How to mitigate CVE-2026-80688

External References

• https://git.kernel.org/stable/c/01bd01b61ad9ea917e5629a7f14f57a8af0543bb
• https://git.kernel.org/stable/c/25f228e6ac573884a3d7078cc2b3312b8db59eea
• https://git.kernel.org/stable/c/f51fed61eea0daba2f95f1a6074085e4cd513c7b

Related Security Bulletins

• Use-after-free in Linux kernel riscv kernel