CVE Catalog

CVE-2026-52973

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.14%

4th percentile - higher than 4% of all known CVEs

Summary

A vulnerability in the Linux kernel futex subsystem where need_futex_hash_allocate_default() incorrectly required CLONE_THREAD for proper hash allocation. This caused a use-after-free bug when sharing memory (mm) in non-thread ways, such as via child processes.

Risk Assessment

The organization risks system crashes or potential data leaks due to memory mismanagement (use-after-free) when processes share address space without using threads.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit removing the CLONE_THREAD requirement and adding CLONE_VM support excluding vfork).

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: futex: Drop CLONE_THREAD requirement for private default hash alloc Currently need_futex_hash_allocate_default() depends on strict pthread semantics, abusing CLONE_THREAD. This breaks the non-concurrency assumptions when doing the mm->futex_ref pcpu allocations, leading to bugs[0] when sharing the mm in other ways; ie: BUG: KASAN: slab-use-after-free in futex_hash_put ... where the +1 bias can end up on a percpu counter that mm->futex_ref no longer points at. Loosen the check to cover any CLONE_VM clone, except vfork(). Excluding vfork keeps the existing paths untouched (no overhead), and we can't race in the first place: either the parent is suspended and the child runs alone, or mm->futex_ref is already allocated from an earlier CLONE_VM.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS