{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52973","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-06-09T07:44:35.375Z","datePublished":"2026-06-24T16:28:51.171Z","dateUpdated":"2026-08-05T12:32:14.948Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:32:14.948Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Drop CLONE_THREAD requirement for private default hash alloc\n\nCurrently need_futex_hash_allocate_default() depends on strict pthread\nsemantics, abusing CLONE_THREAD.  This breaks the non-concurrency\nassumptions when doing the mm->futex_ref pcpu allocations, leading to\nbugs[0] when sharing the mm in other ways; ie:\n\n    BUG: KASAN: slab-use-after-free in futex_hash_put\n\n... where the +1 bias can end up on a percpu counter that mm->futex_ref\nno longer points at.\n\nLoosen the check to cover any CLONE_VM clone, except vfork().  Excluding\nvfork keeps the existing paths untouched (no overhead), and we can't\nrace in the first place: either the parent is suspended and the child\nruns alone, or mm->futex_ref is already allocated from an earlier\nCLONE_VM."}],"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 vulnerable path is reached through local `clone`/`clone3`, `prctl(PR_FUTEX_HASH, ...)`, and futex syscalls on user memory. It is not reachable directly over a network or adjacent/physical interface.\nAC:L - The race is attacker-controlled: an unprivileged process can create multiple `CLONE_VM` non-`CLONE_THREAD` siblings and issue concurrent private futex hash operations. The public report demonstrates a reproducible unprivileged KASAN UAF using attacker-controlled timing aids.\nPR:L - The trigger uses ordinary unprivileged local syscalls and the report reproduced it as UID 1000 without capabilities. No real root or init-namespace administrative privilege is required.\nUI:N - No victim action is needed after the attacker can execute local code. The attacker controls the clone, prctl, userfaultfd, and futex operations.\nS:U - The corruption occurs within the Linux kernel due to local syscall handling and affects the same kernel security authority. There is no hypervisor, IOMMU, or separate-scope boundary crossing.\nC:H - This is a kernel use-after-free of a live `struct futex_private_hash`/bucket array, and UAF memory corruption can reasonably be leveraged for kernel memory disclosure. When uncertain, the higher-severity impact is appropriate.\nI:H - The UAF leaves futex code operating on freed and potentially attacker-reclaimed kernel heap memory, which can plausibly provide write/control-flow primitives. Kernel UAF memory corruption is scored as high integrity impact.\nA:H - The reported impact includes a KASAN slab-use-after-free in `futex_hash_put()` and can crash/oops the kernel. A repeatable local kernel crash is high availability impact."}]}],"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":"d9b05321e21e4b218de4ce8a590bf375f58b6346","lessThan":"1dcd36420af2da5bd59306dba9caf78e3d248b1d","status":"affected","versionType":"git"},{"version":"d9b05321e21e4b218de4ce8a590bf375f58b6346","lessThan":"974ac49a9a068b0591a59f65c63eb06579a13091","status":"affected","versionType":"git"},{"version":"d9b05321e21e4b218de4ce8a590bf375f58b6346","lessThan":"ee9dce44362b2d8132c32964656ab6dff7dfbc6a","status":"affected","versionType":"git"}]},{"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":"6.17","status":"affected"},{"version":"0","lessThan":"6.17","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"6.17","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/1dcd36420af2da5bd59306dba9caf78e3d248b1d"},{"url":"https://git.kernel.org/stable/c/974ac49a9a068b0591a59f65c63eb06579a13091"},{"url":"https://git.kernel.org/stable/c/ee9dce44362b2d8132c32964656ab6dff7dfbc6a"}],"title":"futex: Drop CLONE_THREAD requirement for private default hash alloc","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10.2"],"defaultStatus":"affected","packageName":"kernel","product":"Red Hat Enterprise Linux 10","vendor":"Red Hat","versions":[{"lessThan":"*","status":"unaffected","version":"0:6.12.0-211.39.1.el10_2","versionType":"rpm"}]},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:enterprise_linux:9","cpe:/o:redhat:enterprise_linux:9"],"defaultStatus":"affected","packageName":"kernel","product":"Red Hat Enterprise Linux 9","vendor":"Red Hat","versions":[{"lessThan":"*","status":"unaffected","version":"0:5.14.0-687.31.1.el9_8","versionType":"rpm"}]},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:6"],"defaultStatus":"unaffected","packageName":"kernel","product":"Red Hat Enterprise Linux 6","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"],"defaultStatus":"unaffected","packageName":"kernel","product":"Red Hat Enterprise Linux 7","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"],"defaultStatus":"unaffected","packageName":"kernel-rt","product":"Red Hat Enterprise Linux 7","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"],"defaultStatus":"unaffected","packageName":"kernel","product":"Red Hat Enterprise Linux 8","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"],"defaultStatus":"unaffected","packageName":"kernel-rt","product":"Red Hat Enterprise Linux 8","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"],"defaultStatus":"affected","packageName":"kernel-rt","product":"Red Hat Enterprise Linux 9","vendor":"Red Hat"}],"datePublic":"2026-06-24T00:00:00.000Z","descriptions":[{"lang":"en","value":"A flaw was found in the Linux kernel's futex subsystem. The need_futex_hash_allocate_default() function incorrectly relies on CLONE_THREAD semantics, which can lead to non-concurrency issues when memory allocations (mm->futex_ref pcpu allocations) are shared across CLONE_VM clones, excluding vfork(). This can result in a use-after-free vulnerability in futex_hash_put, a form of memory corruption. Such vulnerabilities can potentially lead to system instability or other security impacts."}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-825","description":"Expired Pointer Dereference","lang":"en","type":"CWE"}]}],"references":[{"tags":["vdb-entry","x_refsource_REDHAT"],"url":"https://access.redhat.com/security/cve/CVE-2026-52973"},{"name":"RHBZ#2492413","tags":["issue-tracking","x_refsource_REDHAT"],"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492413"},{"tags":["x_sadp-csaf-vex"],"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52973.json"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:45114"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:47040"}],"solutions":[{"lang":"en","value":"RHSA-2026:45114: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10)"},{"lang":"en","value":"RHSA-2026:47040: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9)"}],"timeline":[{"lang":"en","time":"2026-06-24T00:00:00.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-06-24T00:00:00.000Z","value":"Made public."}],"title":"kernel: futex: Drop CLONE_THREAD requirement for private default hash alloc","x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"},"providerMetadata":{"orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","shortName":"redhat-SADP","dateUpdated":"2026-07-29T12:04:38.152Z"}}]}}