CVE-2026-43266

System crash via oversized CPER section length

Published May 6, 2026 · Updated May 6, 2026

Out-of-bounds read in Linux Kernel EFI/CPER handling allows local users to crash ARM systems via a malformed firmware error record. The ARM processor record parser trusts section_length and ERR_INFO_NUM without checking that iteration stays within the CPER buffer, so error dumping reads beyond the firmware-mapped area. Exposure requires an affected ARM system with GHES/CPER active and a malformed record supplied through firmware; the grounded impact is a system crash.

CVSS severity5.5
Medium
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

Out-of-bounds read in Linux Kernel EFI/CPER handling allows local users to crash ARM systems via a malformed firmware error record. The ARM processor record parser trusts section_length and ERR_INFO_NUM without checking that iteration stays within the CPER buffer, so error dumping reads beyond the firmware-mapped area. Exposure requires an affected ARM system with GHES/CPER active and a malformed record supplied through firmware; the grounded impact is a system crash.

The record

CVE
CVE-2026-43266
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-130, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <25b290624b0e3d2f0f90238709ee0b6009b9fde8
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <45766863baf899059e75595dd3cb1116467f2095
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <64eb63f573f497553e1a0c388bbcdd639e0f0704
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a68d22902a6916e10ee235fee609239004e129d0
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <be10c1bdf64a39832998f54900aa309b3917abcf
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c80113dcfc807308f5ab33847fae77e07531aeb8
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ca2aad8771aa9091bc9e42e7d546bd40b72ddcd4
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <eae21beecb95a3b69ee5c38a659f774e171d730e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <25b290624b0e3d2f0f90238709ee0b6009b9fde8; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <45766863baf899059e75595dd3cb1116467f2095; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <64eb63f573f497553e1a0c388bbcdd639e0f0704; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a68d22902a6916e10ee235fee609239004e129d0; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <be10c1bdf64a39832998f54900aa309b3917abcf; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c80113dcfc807308f5ab33847fae77e07531aeb8; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ca2aad8771aa9091bc9e42e7d546bd40b72ddcd4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <eae21beecb95a3b69ee5c38a659f774e171d730e

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Red HatCVSS: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

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-130Improper Handling of Length Parameter Inconsistency
T1499.004Application or System Exploitation

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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