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CVE Record

CVE-2026-52973: futex: Drop CLONE_THREAD requirement for private default hash alloc

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.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-52973 is a Linux kernel futex memory-lifetime bug. A local authenticated user could potentially trigger use-after-free behavior in kernel futex reference handling, with high impact to confidentiality, integrity, and availability. This is most urgent for shared systems, container hosts, and multi-user Linux environments.

Executive priority

Treat as high priority for multi-user and containerized Linux environments. It is not remotely exploitable from the supplied evidence, but kernel memory corruption with low local privileges can materially affect system trust.

Technical view

The fix changes futex default hash allocation logic from relying on CLONE_THREAD to covering CLONE_VM clones except vfork. The prior check could allow mm->futex_ref per-CPU allocations to be freed or referenced incorrectly, producing KASAN slab-use-after-free in futex_hash_put. CVSS is 7.8 with local, low-complexity, low-privilege attack requirements.

Likely exposure

Exposure is Linux-kernel dependent. The source marks Linux affected for listed version entries including 6.17, 6.18.33, 7.0.10, and 7.1, but distribution package impact needs vendor confirmation.

Exploitation context

No active exploitation is stated in the provided sources, and the KEV flag is false. The CVSS vector indicates exploitation requires local access and low privileges, with no user interaction.

Researcher notes

The available detail points to CWE-825 and a futex_hash_put use-after-free caused by incorrect assumptions around shared mm users. Source evidence gives fix direction, but does not provide distribution-level affected package lists or exploit-in-the-wild evidence.

Mitigation direction

  • Apply kernel updates containing the referenced stable futex fix commits.
  • Check distribution advisories, especially Red Hat guidance, for package-specific status.
  • Prioritize shared Linux hosts, container platforms, and developer jump boxes.
  • Limit unnecessary local shell access until patched.
  • Track vendor VEX or errata updates for affected product mapping.

Validation and detection

  • Inventory running Linux kernel versions across servers and workstations.
  • Compare kernel builds against vendor advisories and referenced stable commits.
  • Identify systems with untrusted or broad local user access.
  • Confirm updated kernels are booted after patching.
  • Monitor kernel logs for futex-related crashes or KASAN findings.
Prepared
Confidence
medium
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-825: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-52973 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
1ADP providers
7Source links

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux
7CVSS 3.1HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H15.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-52973Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

redhat-SADPkernel: futex: Drop CLONE_THREAD requirement for private default hash alloc
other:Red Hat severity ratingcvssV3_1
  • 2026-06-24T00:00:00.000Z: Reported to Red Hat.
  • 2026-06-24T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxd9b05321e21e4b218de4ce8a590bf375f58b6346, d9b05321e21e4b218de4ce8a590bf375f58b6346, d9b05321e21e4b218de4ce8a590bf375f58b6346unaffected
LinuxLinux6.17, 0, 6.18.33, 7.0.10, 7.1affected
Weakness

CWE details

CWE-825

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-825 · source CWE mapping

Expired Pointer Dereference

Expired Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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