CVE-2025-40081

Kernel memory corruption via signed AUX-buffer shift

Published Oct 28, 2025 · Updated Oct 28, 2025

Integer overflow in Linux kernel Arm SPE perf support allows local users to corrupt kernel memory through a 2 GiB AUX buffer. PERF_IDX2OFF shifts the signed nr_pages value before widening it, so the offset wraps and drives CPU or memset writes beyond the vmalloc buffer. The path requires Arm SPE hardware and local perf_event_open access; exploitation can disclose or overwrite kernel memory or trigger an oops or panic.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Linux kernel Arm SPE perf support allows local users to corrupt kernel memory through a 2 GiB AUX buffer. PERF_IDX2OFF shifts the signed nr_pages value before widening it, so the offset wraps and drives CPU or memset writes beyond the vmalloc buffer. The path requires Arm SPE hardware and local perf_event_open access; exploitation can disclose or overwrite kernel memory or trigger an oops or panic.

The record

CVE
CVE-2025-40081
Published
Oct 28, 2025
Updated
Oct 28, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 2025Record 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=4.15
  2. Affected versionversion=d5d9696b03808bc6be723cc85288c912c3a05606 <1a19ba8e1f4ff24ece8ca69b79df8442c431db90
  3. Affected versionversion=d5d9696b03808bc6be723cc85288c912c3a05606 <379cae2cb982f571cda9493ac573ab71125fd299
  4. Affected versionversion=d5d9696b03808bc6be723cc85288c912c3a05606 <5d01f2b81568289443d22f1e13a363f829de6343
  5. Affected versionversion=d5d9696b03808bc6be723cc85288c912c3a05606 <7500384d3c9587593d75ded3b006835e7aa73ef8
  6. Affected versionversion=d5d9696b03808bc6be723cc85288c912c3a05606 <a29fea30dd93da16652930162b177941abd8c75e
  7. Affected versionversion=d5d9696b03808bc6be723cc85288c912c3a05606 <e516cfd19b0f4c774a57b17fb43a7f41991f0735

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.15; version=d5d9696b03808bc6be723cc85288c912c3a05606 <1a19ba8e1f4ff24ece8ca69b79df8442c431db90; version=d5d9696b03808bc6be723cc85288c912c3a05606 <379cae2cb982f571cda9493ac573ab71125fd299; version=d5d9696b03808bc6be723cc85288c912c3a05606 <5d01f2b81568289443d22f1e13a363f829de6343; version=d5d9696b03808bc6be723cc85288c912c3a05606 <7500384d3c9587593d75ded3b006835e7aa73ef8; version=d5d9696b03808bc6be723cc85288c912c3a05606 <a29fea30dd93da16652930162b177941abd8c75e; version=d5d9696b03808bc6be723cc85288c912c3a05606 <e516cfd19b0f4c774a57b17fb43a7f41991f0735

Published CVSS scores

7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
4.4Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
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

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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

T1499.004Application or System Exploitation
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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