CVE-2026-43025

Kernel memory disclosure via mismatched expectation helper

Published May 1, 2026 · Updated May 1, 2026

Out-of-bounds read in Linux Kernel netfilter allows local users to disclose kernel memory through a crafted ctnetlink expectation. In nf_conntrack_netlink.c, ctnetlink_create_expect accepts a userspace-supplied helper that differs from the master conntrack helper, then CTA_EXPECT_CLASS validation reads beyond the selected helper's expectation-policy array. Local low-privileged access and the ability to create the mismatched netfilter expectation are required; the demonstrated consequence is disclosure of kernel-memory bytes.

CVSS severity7.3
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux Kernel netfilter allows local users to disclose kernel memory through a crafted ctnetlink expectation. In nf_conntrack_netlink.c, ctnetlink_create_expect accepts a userspace-supplied helper that differs from the master conntrack helper, then CTA_EXPECT_CLASS validation reads beyond the selected helper's expectation-policy array. Local low-privileged access and the ability to create the mismatched netfilter expectation are required; the demonstrated consequence is disclosure of kernel-memory bytes.

The record

CVE
CVE-2026-43025
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=3.12
  2. Affected versionversion=bd0779370588386e4a67ba5d0b176cfded8e6a53 <0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cd
  3. Affected versionversion=bd0779370588386e4a67ba5d0b176cfded8e6a53 <187b6ec5229ea93cb04c4f6d3b52efc80f513d0d
  4. Affected versionversion=bd0779370588386e4a67ba5d0b176cfded8e6a53 <21a04c31db4057deec85fcd6cc63d720b38819c3
  5. Affected versionversion=bd0779370588386e4a67ba5d0b176cfded8e6a53 <2ea0f35f235f70c133ad61fe05ba013753b978c6
  6. Affected versionversion=bd0779370588386e4a67ba5d0b176cfded8e6a53 <917b61fa2042f11e2af4c428e43f08199586633a
  7. Affected versionversion=bd0779370588386e4a67ba5d0b176cfded8e6a53 <e135f8e8212cbed12a03ab8dec77fa1247139897

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.12; version=bd0779370588386e4a67ba5d0b176cfded8e6a53 <0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cd; version=bd0779370588386e4a67ba5d0b176cfded8e6a53 <187b6ec5229ea93cb04c4f6d3b52efc80f513d0d; version=bd0779370588386e4a67ba5d0b176cfded8e6a53 <21a04c31db4057deec85fcd6cc63d720b38819c3; version=bd0779370588386e4a67ba5d0b176cfded8e6a53 <2ea0f35f235f70c133ad61fe05ba013753b978c6; version=bd0779370588386e4a67ba5d0b176cfded8e6a53 <917b61fa2042f11e2af4c428e43f08199586633a; version=bd0779370588386e4a67ba5d0b176cfded8e6a53 <e135f8e8212cbed12a03ab8dec77fa1247139897

Published CVSS scores

7.3kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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

CWE-125Out-of-bounds Read

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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