CVE-2026-43427

Kernel memory disclosure via reordered buffer update

Published May 8, 2026 · Updated May 8, 2026

Out-of-bounds read in the Linux Kernel cdc-wdm driver allows local users to read uninitialized kernel memory through a device read. In wdm_read(), desc->length can become visible before memmove finishes, so copy_to_user() copies bytes that the buffer has not initialized. Exploitation requires local low-privileged access to a cdc-wdm device and a timing-dependent race; no write or code-execution impact is reported.

CVSS severity7.1
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 the Linux Kernel cdc-wdm driver allows local users to read uninitialized kernel memory through a device read. In wdm_read(), desc->length can become visible before memmove finishes, so copy_to_user() copies bytes that the buffer has not initialized. Exploitation requires local low-privileged access to a cdc-wdm device and a timing-dependent race; no write or code-execution impact is reported.

The record

CVE
CVE-2026-43427
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 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=2.6.26
  2. Affected versionversion=afba937e540c902c989cd516fd97ea0c8499bb27 <170e8daca24da6edb4be82ab01abf44e87af387b
  3. Affected versionversion=afba937e540c902c989cd516fd97ea0c8499bb27 <276aef0fd2b92f41b920ac891c72cadeee957934
  4. Affected versionversion=afba937e540c902c989cd516fd97ea0c8499bb27 <4ee3062bf2c9a722afef429826e8607eaf3fc6a0
  5. Affected versionversion=afba937e540c902c989cd516fd97ea0c8499bb27 <638328ca9c17ae6511ad62198c57bae32ffa3c91
  6. Affected versionversion=afba937e540c902c989cd516fd97ea0c8499bb27 <67ed312124bb1b61858778ac0b985b48961c862a
  7. Affected versionversion=afba937e540c902c989cd516fd97ea0c8499bb27 <8df672bfe3ec2268c2636584202755898e547173
  8. Affected versionversion=afba937e540c902c989cd516fd97ea0c8499bb27 <c8fa96ed021923dae147bcd9f9205b8df7b82360
  9. Affected versionversion=afba937e540c902c989cd516fd97ea0c8499bb27 <e3c874b05901dc519054b5107d16620e6d2b5fea

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.26; version=afba937e540c902c989cd516fd97ea0c8499bb27 <170e8daca24da6edb4be82ab01abf44e87af387b; version=afba937e540c902c989cd516fd97ea0c8499bb27 <276aef0fd2b92f41b920ac891c72cadeee957934; version=afba937e540c902c989cd516fd97ea0c8499bb27 <4ee3062bf2c9a722afef429826e8607eaf3fc6a0; version=afba937e540c902c989cd516fd97ea0c8499bb27 <638328ca9c17ae6511ad62198c57bae32ffa3c91; version=afba937e540c902c989cd516fd97ea0c8499bb27 <67ed312124bb1b61858778ac0b985b48961c862a; version=afba937e540c902c989cd516fd97ea0c8499bb27 <8df672bfe3ec2268c2636584202755898e547173; version=afba937e540c902c989cd516fd97ea0c8499bb27 <c8fa96ed021923dae147bcd9f9205b8df7b82360; version=afba937e540c902c989cd516fd97ea0c8499bb27 <e3c874b05901dc519054b5107d16620e6d2b5fea

Published CVSS scores

5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/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-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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