Is CVE-2026-52973 being actively exploited?

It is not currently in CISA's KEV catalog. Its EPSS exploitation probability is 0%.

What products does CVE-2026-52973 affect?

Tracked products affected include Linux Kernel. Check the version you run to see whether it is affected.

How do I fix CVE-2026-52973?

Apply the vendor fix promptly. An official patch or advisory is available. Upgrade affected products to a fixed version.

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CVE-2026-52973

Q: What is CVE-2026-52973?

CVE-2026-52973 is a high-severity software vulnerability (Use-after-free) with a CVSS score of 7.8. 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

HIGH severity · CVSS 7.8 · Use-after-free

7.8CVSS HIGH

Summary

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.

Impact & exploitability

Attack vectorLocal

Attack complexityLow

Privileges requiredLow

User interactionNone

Confidentiality impactHigh

Integrity impactHigh

Availability impactHigh

Exploit probability (EPSS)0%

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products we track (1)

Linux Kernel

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/1dcd36420af2da5bd59306dba9caf78e3d248b1d ↗

CVE-2026-52973

Summary

Impact & exploitability

Affected products we track (1)

Recommendation

Additional information