{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98281","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.335Z","datePublished":"2026-10-06T08:45:40.719Z","dateUpdated":"2026-10-07T06:49:52.329Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-07T06:49:52.329Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Also allocate private hash on vfork()\n\nAs Jann demonstrated, it is entirely feasible to access the mm through vfork().\nTherefore we need to allocate a private hash on vfork() as well as any other\nCLONE_VM user.\n\nSpecifically, it must be avoided to have (private) futex waiters before\nallocating the private hash."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The trigger is a local process calling vfork()/clone3(CLONE_VM|CLONE_VFORK) in kernel_clone()/copy_process(), where need_futex_hash_allocate_default() skipped the private hash, followed by futex() syscalls on the shared mm. No remote peer supplies any input.\nAC:L - The attacker owns every task involved: the vfork parent (killed through its TASK_KILLABLE wait_for_vfork_done, so its futex exit path runs on the shared mm) and the vfork child, which creates a thread to publish the first private hash. Both sides of the race are under attacker control, so it can be retried at will.\nPR:L - vfork, clone, futex(FUTEX_WAIT/LOCK_PI), robust lists and kill() all work for an ordinary unprivileged user with no capability checks. The hash allocation in futex_hash_allocate_default() has no privilege gate either.\nUI:N - The attacker's own processes create the shared-mm state and the futex operations. No other user has to do anything.\nS:U - The damaged objects are kernel futex state (mm->futex.phash, hash buckets, pi_state) inside the same kernel security authority. No guest/host or IOMMU boundary is crossed.\nC:H - __futex_pivot_hash() leaves waiters queued in the global hash when the private hash is first published, so later PI/requeue operations take a different bucket lock. Futex PI state handled under two different bucket locks is the classic futex use-after-free pattern, and the earlier bug from this same assumption was a KASAN use-after-free, so kernel memory disclosure is plausible.\nI:H - A freed pi_state or private-hash reference that the attacker can reallocate gives a kernel heap write primitive, as in earlier futex PI use-after-free exploits, so local privilege escalation is possible.\nA:H - Waiters stranded in the global hash miss every later wake that goes to the private bucket, which hangs the affected tasks. The pi_state/reference corruption from inconsistent bucket locking can cause a KASAN splat or kernel oops."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/fork.c"],"versions":[{"version":"1dcd36420af2da5bd59306dba9caf78e3d248b1d","lessThan":"5468a4855b63b30156a79e5248e01bf1a2c18dd7","status":"affected","versionType":"git"},{"version":"ee9dce44362b2d8132c32964656ab6dff7dfbc6a","lessThan":"eecbafa8cabbc4d1482f6a5e2acc25a8f934681b","status":"affected","versionType":"git"},{"version":"ee9dce44362b2d8132c32964656ab6dff7dfbc6a","lessThan":"b61b6f95d6722ddbbbd09e689fa41b55fd36f9a5","status":"affected","versionType":"git"},{"version":"974ac49a9a068b0591a59f65c63eb06579a13091","status":"affected","versionType":"git"},{"version":"6.18.33","lessThan":"6.18.54","status":"affected","versionType":"semver"},{"version":"7.0.10","lessThan":"7.1","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/fork.c"],"versions":[{"version":"7.1","status":"affected"},{"version":"0","lessThan":"7.1","status":"unaffected","versionType":"semver"},{"version":"6.18.54","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.8","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc4","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18.33","versionEndExcluding":"6.18.54"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.2.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.3-rc4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0.10"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/5468a4855b63b30156a79e5248e01bf1a2c18dd7"},{"url":"https://git.kernel.org/stable/c/eecbafa8cabbc4d1482f6a5e2acc25a8f934681b"},{"url":"https://git.kernel.org/stable/c/b61b6f95d6722ddbbbd09e689fa41b55fd36f9a5"}],"title":"futex: Also allocate private hash on vfork()","x_generator":{"engine":"bippy-1.2.0"}}}}