CVE-2026-52973

Kernel memory corruption via stale futex counter

Published Jun 24, 2026 · Updated Jun 24, 2026

Use-after-free in Linux Kernel 6.17's futex subsystem allows local users to corrupt kernel memory through CLONE_VM cloning. The need_futex_hash_allocate_default() check keys allocation only to CLONE_THREAD, so other shared-mm clones can leave the futex_ref bias on a freed per-CPU counter. A low-privileged local account that can create a non-vfork CLONE_VM process can trigger the stale access, causing memory corruption or a kernel crash.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux Kernel 6.17's futex subsystem allows local users to corrupt kernel memory through CLONE_VM cloning. The need_futex_hash_allocate_default() check keys allocation only to CLONE_THREAD, so other shared-mm clones can leave the futex_ref bias on a freed per-CPU counter. A low-privileged local account that can create a non-vfork CLONE_VM process can trigger the stale access, causing memory corruption or a kernel crash.

The record

CVE
CVE-2026-52973
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.17
  2. Affected versionversion=d9b05321e21e4b218de4ce8a590bf375f58b6346 <1dcd36420af2da5bd59306dba9caf78e3d248b1d
  3. Affected versionversion=d9b05321e21e4b218de4ce8a590bf375f58b6346 <974ac49a9a068b0591a59f65c63eb06579a13091
  4. Affected versionversion=d9b05321e21e4b218de4ce8a590bf375f58b6346 <ee9dce44362b2d8132c32964656ab6dff7dfbc6a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.17; version=d9b05321e21e4b218de4ce8a590bf375f58b6346 <1dcd36420af2da5bd59306dba9caf78e3d248b1d; version=d9b05321e21e4b218de4ce8a590bf375f58b6346 <974ac49a9a068b0591a59f65c63eb06579a13091; version=d9b05321e21e4b218de4ce8a590bf375f58b6346 <ee9dce44362b2d8132c32964656ab6dff7dfbc6a

Published CVSS scores

7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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