CVE-2026-23271

Local privilege escalation via perf event use-after-free

Published Mar 20, 2026 · Updated Mar 20, 2026

Use-after-free in Linux Kernel 2.6.31 through affected branches allows local users to execute arbitrary code in kernel context. __perf_event_overflow() can run for software events with preemption disabled but IRQs enabled, while perf_event_exit_event() frees the event and its BPF program. An unprivileged local user can create software perf events under the default perf_event_paranoid=2 setting and race overflow against closing the event file descriptor, enabling kernel-memory access, kernel code execution, or a crash.

CVSS severity7.8
High
EPSS probability0.10%
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 2.6.31 through affected branches allows local users to execute arbitrary code in kernel context. __perf_event_overflow() can run for software events with preemption disabled but IRQs enabled, while perf_event_exit_event() frees the event and its BPF program. An unprivileged local user can create software perf events under the default perf_event_paranoid=2 setting and race overflow against closing the event file descriptor, enabling kernel-memory access, kernel code execution, or a crash.

The record

CVE
CVE-2026-23271
Published
Mar 20, 2026
Updated
Mar 20, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 20, 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=2.6.31
  2. Affected versionversion=592903cdcbf606a838056bae6d03fc557806c914 <3f89b61dd504c5b6711de9759e053b082f9abf12
  3. Affected versionversion=592903cdcbf606a838056bae6d03fc557806c914 <5c48fdc4b4623533d86e279f51531a7ba212eb87
  4. Affected versionversion=592903cdcbf606a838056bae6d03fc557806c914 <bb190628fe5f2a73ba762a9972ba16c5e895f73e
  5. Affected versionversion=592903cdcbf606a838056bae6d03fc557806c914 <c9bc1753b3cc41d0e01fbca7f035258b5f4db0ae

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.31; version=592903cdcbf606a838056bae6d03fc557806c914 <3f89b61dd504c5b6711de9759e053b082f9abf12; version=592903cdcbf606a838056bae6d03fc557806c914 <5c48fdc4b4623533d86e279f51531a7ba212eb87; version=592903cdcbf606a838056bae6d03fc557806c914 <bb190628fe5f2a73ba762a9972ba16c5e895f73e; version=592903cdcbf606a838056bae6d03fc557806c914 <c9bc1753b3cc41d0e01fbca7f035258b5f4db0ae

Published CVSS scores

7.8Linux kernel CVE teamCVSS: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

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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