{ "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": "2026-10-19T09:16:52.791Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:16:52.791Z" }, "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", "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" }, { "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" } } } }