CVE-2026-52933

Local kernel compromise via signed poll_refs comparison

Published Jun 24, 2026 · Updated Jun 24, 2026

Improper signed comparison in Linux Kernel io_uring poll handling allows local users to compromise confidentiality, integrity, and availability. The io_poll_get_ownership() function reads poll_refs as a signed int, so setting BIT(31) makes the value negative and bypasses the >=128 slowpath check. Exploitation requires low-privileged local access and a set cancellation flag; public records do not describe the final corruption path.

CVSS severity7.8
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper signed comparison in Linux Kernel io_uring poll handling allows local users to compromise confidentiality, integrity, and availability. The io_poll_get_ownership() function reads poll_refs as a signed int, so setting BIT(31) makes the value negative and bypasses the >=128 slowpath check. Exploitation requires low-privileged local access and a set cancellation flag; public records do not describe the final corruption path.

The record

CVE
CVE-2026-52933
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-835, T1068
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

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Is a vulnerable build present?

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

  1. Affected versionversion=4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048
  2. Affected versionversion=5.15.82 <5.16
  3. Affected versionversion=6.0.11 <6.1
  4. Affected versionversion=6.1
  5. Affected versionversion=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <326941b22806cbf2df1fbfe902b7908b368cce42
  6. Affected versionversion=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <81bf96b0abbfa4cd47ea32e12596aed3855fb2f3
  7. Affected versionversion=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <c6d191164dc81838d8dbf452a6000f68c558d1ae
  8. Affected versionversion=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <cf522703d4f194991615763697ae25a3f9539763
  9. Affected versionversion=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <ea0697129807d718037f618221037aa0660ee3c5
  10. Affected versionversion=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <fc47043f3d9af3efa407665b47f8378ec691ba18
  11. Affected versionversion=bc4e6ee16778149811333a969a7a893d4cc110c5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048; version=5.15.82 <5.16; version=6.0.11 <6.1; version=6.1; version=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <326941b22806cbf2df1fbfe902b7908b368cce42; version=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <81bf96b0abbfa4cd47ea32e12596aed3855fb2f3; version=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <c6d191164dc81838d8dbf452a6000f68c558d1ae; version=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <cf522703d4f194991615763697ae25a3f9539763; version=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <ea0697129807d718037f618221037aa0660ee3c5; version=a26a35e9019fd70bf3cf647dcfdae87abc7bacea <fc47043f3d9af3efa407665b47f8378ec691ba18; version=bc4e6ee16778149811333a969a7a893d4cc110c5

Published CVSS scores

7.8LinuxCVSS: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-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1068Exploitation for Privilege Escalation

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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