CVE-2026-80758: Linux kernel · futex: Avoid private hash use-after-free on final put
Source GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 4 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: futex: Avoid private hash use-after-free on final put futex_private_hash_put() drops the reference to fph before evaluating fph->mm for wake_up_var(). futex_ref_put() enables preemption again before returning. If that put drops the final reference and the task is preempted, another task can pivot to the replacement hash and free the old hash after an RCU grace period. The first task then reads fph->mm from the freed allocation when it resumes. KASAN reports a slab-use-after-free in futex_private_hash_put(), with the read at offset 24 in a freed kmalloc-512 allocation. The allocation and free stacks point to futex_hash_allocate() and the RCU free path, respectively. Load the mm pointer while the fph reference is still held and pass the saved value to wake_up_var(). wake_up_var() uses the pointer as a waitqueue key and does not dereference the mm through it.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80758 (opens in a new tab)
- git.kernel.org/stable/c/12cd315a7b6a7d7db3f69d98bfe3909275e9451d (opens in a new tab)
- git.kernel.org/stable/c/1c7efabfbaf796f11000a46094a69955a01ec6cc (opens in a new tab)
- git.kernel.org/stable/c/25408c62ed4ebcd491d0e9e4b4a5b512547512e4 (opens in a new tab)
- git.kernel.org/stable/c/dba60d26e9dda3e157ad6b0934d4232f6c6904ee (opens in a new tab)