CVE-2026-52973futex: Drop CLONE_THREAD requirement for private default hash alloc
- 7.8HighCVSS base score
- 0.18%Exploitation in 30 daysEPSS · top 92% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Linux
- 15 days later
· 15 days later
Published
- 4 months later
· 4 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| redhat-SADPADP (enrichment) | 3.1 | High7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.18% · top 92% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected d9b05321e21e4b218de4ce8a590bf375f58b6346 – < 1dcd36420af2da5bd59306dba9caf78e3d248b1d
- affected d9b05321e21e4b218de4ce8a590bf375f58b6346 – < 974ac49a9a068b0591a59f65c63eb06579a13091
- affected d9b05321e21e4b218de4ce8a590bf375f58b6346 – < ee9dce44362b2d8132c32964656ab6dff7dfbc6a
- affected 6.17
- unaffected < 6.17
- unaffected 6.18.33 – ≤ 6.18.*
- unaffected 7.0.10 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References10
- https://git.kernel.org/stable/c/1dcd36420af2da5bd59306dba9caf78e3d248b1d (opens in a new tab)
- https://git.kernel.org/stable/c/974ac49a9a068b0591a59f65c63eb06579a13091 (opens in a new tab)
- https://git.kernel.org/stable/c/ee9dce44362b2d8132c32964656ab6dff7dfbc6a (opens in a new tab)
- https://access.redhat.com/security/cve/CVE-2026-52973 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2492413 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52973.json (opens in a new tab)x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:45114 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:47040 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:62642 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:62640 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-38841 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-52973)Record last updated .