CVE-2026-43281

Memory disclosure or crash via unchecked mailbox index

Published May 6, 2026 · Updated May 6, 2026

Out-of-bounds read in Linux Kernel mailbox handling allows local users to disclose kernel memory or crash via a zero-cell mailbox reference. fw_mbox_index_xlate() reads sp->args[0] without first verifying that sp->nargs is nonzero when #mbox-cells equals zero. The fallback is reached only when the mailbox controller supplies neither fw_xlate nor of_xlate, and exploitation requires local low-privileged access.

CVSS severity7.1
High
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 mailbox handling allows local users to disclose kernel memory or crash via a zero-cell mailbox reference. fw_mbox_index_xlate() reads sp->args[0] without first verifying that sp->nargs is nonzero when #mbox-cells equals zero. The fallback is reached only when the mailbox controller supplies neither fw_xlate nor of_xlate, and exploitation requires local low-privileged access.

The record

CVE
CVE-2026-43281
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125
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 <01d9a8c2615d436b2b30c19c1afe9fcd5726ff6d
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2662ed331a69c0b551f78af58f12eb629a89a36f
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <31c4c67dec3362094a6747a171a4848e98542265
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4caae8168d1b808c7d4ff481295292e3f97f90fb
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f50b39fd7c72a8734153644ee945ca0d8b2e65ab
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fcd7f96c783626c07ee3ed75fa3739a8a2052310

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <01d9a8c2615d436b2b30c19c1afe9fcd5726ff6d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2662ed331a69c0b551f78af58f12eb629a89a36f; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <31c4c67dec3362094a6747a171a4848e98542265; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4caae8168d1b808c7d4ff481295292e3f97f90fb; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f50b39fd7c72a8734153644ee945ca0d8b2e65ab; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fcd7f96c783626c07ee3ed75fa3739a8a2052310

Published CVSS scores

7.1UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
7.1Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.1NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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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