CVE-2026-43494Public exploit

Local privilege escalation via stale zerocopy page count

Published May 21, 2026 · Updated May 21, 2026

A double release in Linux Kernel RDS zerocopy handling allows local users to gain root privileges after a page-pin operation fails. rds_message_zcopy_from_user() releases pinned pages but leaves op_nents nonzero, so rds_message_purge() later releases the same pages again. Local access and reachability of the RDS zerocopy path are required; reclaimed pages can be used to overwrite privileged file-cache contents.

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

What happened

A double release in Linux Kernel RDS zerocopy handling allows local users to gain root privileges after a page-pin operation fails. rds_message_zcopy_from_user() releases pinned pages but leaves op_nents nonzero, so rds_message_purge() later releases the same pages again. Local access and reachability of the RDS zerocopy path are required; reclaimed pages can be used to overwrite privileged file-cache contents.

The record

CVE
CVE-2026-43494
Published
May 21, 2026
Updated
May 21, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-1341, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2026CVE publishedPublication date reported by the CVE source.
  2. May 21, 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=0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 <e174929793195e0cd6a4adb0cad731b39f9019b4
  2. Affected versionversion=4.17

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 <e174929793195e0cd6a4adb0cad731b39f9019b4; version=4.17

Published CVSS scores

7.0redhat-SADPCVSS: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 exploitPublished

Weakness, pattern, technique

CWE-1341Multiple Releases of Same Resource or Handle
T1068Exploitation for Privilege Escalation

Public exploit references

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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