CVE-2026-43277

Kernel crash via oversized CPER firmware record

Published May 6, 2026 · Updated May 6, 2026

Out-of-bounds read in affected Linux Kernel releases allows local users to cause a kernel OOPS via malformed CPER firmware data. The APEI/GHES path validates the reported CPER length against the 64 KB GHES_ESTATUS_MAX_SIZE limit instead of the smaller page-backed allocation, then prints beyond that allocation. Reachability requires firmware-controlled CPER data and low local privileges; the demonstrated consequence is a kernel OOPS and service interruption, not data modification or disclosure.

CVSS severity5.5
Medium
EPSS probability0.11%
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 affected Linux Kernel releases allows local users to cause a kernel OOPS via malformed CPER firmware data. The APEI/GHES path validates the reported CPER length against the 64 KB GHES_ESTATUS_MAX_SIZE limit instead of the smaller page-backed allocation, then prints beyond that allocation. Reachability requires firmware-controlled CPER data and low local privileges; the demonstrated consequence is a kernel OOPS and service interruption, not data modification or disclosure.

The record

CVE
CVE-2026-43277
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
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 <616c120dcdf1ce96edcd818e38bce49667f80689
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6f5d41984ad896736c23e2fff7c80e15c1319132
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <92ba79074c58e65a6e32713758c5a9aecd33c2ea
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <98bd9b28d4d11e6739ad86524b4be4ada9025e60
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b6be51a12441136fdf8c49b2525689fbea1856e1
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e0ec99115e135dbb58e11a0df007c7d4771d4a17
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f3740a1562445f36f08afab8af59e37117b3acdc
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fa2408a24f8f0db14d9cfc613ef162dc267d7ad4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <616c120dcdf1ce96edcd818e38bce49667f80689; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6f5d41984ad896736c23e2fff7c80e15c1319132; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <92ba79074c58e65a6e32713758c5a9aecd33c2ea; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <98bd9b28d4d11e6739ad86524b4be4ada9025e60; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b6be51a12441136fdf8c49b2525689fbea1856e1; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e0ec99115e135dbb58e11a0df007c7d4771d4a17; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f3740a1562445f36f08afab8af59e37117b3acdc; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fa2408a24f8f0db14d9cfc613ef162dc267d7ad4

Published CVSS scores

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

T1499Endpoint Denial of Service

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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