CVE-2026-52973
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Linux Kernel < 6.18.33
- Linux Kernel < 7.0.10
- Linux Kernel 6.17
- Linux Kernel 7.1
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-52973.md and follow it. Check whether this project is affected by CVE-2026-52973. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/1dcd36420af2da5bd59306dba9caf78e3d248b1d
- https://git.kernel.org/stable/c/974ac49a9a068b0591a59f65c63eb06579a13091
- https://git.kernel.org/stable/c/ee9dce44362b2d8132c32964656ab6dff7dfbc6a
References
- https://git.kernel.org/stable/c/1dcd36420af2da5bd59306dba9caf78e3d248b1d
- https://git.kernel.org/stable/c/974ac49a9a068b0591a59f65c63eb06579a13091
- https://git.kernel.org/stable/c/ee9dce44362b2d8132c32964656ab6dff7dfbc6a
- https://access.redhat.com/errata/RHSA-2026:45114
- https://access.redhat.com/errata/RHSA-2026:47040
- https://access.redhat.com/errata/RHSA-2026:62640
- https://access.redhat.com/errata/RHSA-2026:62642
- https://access.redhat.com/security/cve/CVE-2026-52973
- https://bugzilla.redhat.com/show_bug.cgi?id=2492413
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52973.json