CVE-2026-43252

Service interruption via unreleased MPTCP endpoint IDs

Published May 6, 2026 · Updated May 6, 2026

Improper locking in the Linux Kernel MPTCP path manager allows local users to trigger a kernel warning and service interruption. When an endpoint is removed, mptcp_pm_remove_addrs_and_subflows fails to return Signal or MPC endpoint IDs to id_avail_bitmap, leaving endpoint state inconsistent. Low-privileged local access is required, and a specific sequence of MPTCP generic-netlink endpoint operations reaches the warning path.

CVSS severity5.5
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in the Linux Kernel MPTCP path manager allows local users to trigger a kernel warning and service interruption. When an endpoint is removed, mptcp_pm_remove_addrs_and_subflows fails to return Signal or MPC endpoint IDs to id_avail_bitmap, leaving endpoint state inconsistent. Low-privileged local access is required, and a specific sequence of MPTCP generic-netlink endpoint operations reaches the warning path.

The record

CVE
CVE-2026-43252
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-667, 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=027cca7029bee685a5ca5c4849be5a2c446ce046 <d90d73ad183566c81320d453a223f610a280f210
  2. Affected versionversion=47a049b38f567a2fbec76bc211ad7ad735519607
  3. Affected versionversion=6.11
  4. Affected versionversion=cb24bdcdecba1c60169efb74d88900888df59907 <1b3ff4d88b508b73e2bbddb59356311efb7ba192
  5. Affected versionversion=e255683c06df572ead96db5efb5d21be30c0efaa <4d480efd98e290c445f4ba476e4dcda5624b1aab
  6. Affected versionversion=e255683c06df572ead96db5efb5d21be30c0efaa <7c1d221e475e3d8eb8ed4702392d43f8c5134d1f
  7. Affected versionversion=e255683c06df572ead96db5efb5d21be30c0efaa <7e4d88e36e5d0b8ffda637999cbca64c81701a81
  8. Affected versionversion=e255683c06df572ead96db5efb5d21be30c0efaa <d191101dee25567c2af3b28565f45346c33d65f5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=027cca7029bee685a5ca5c4849be5a2c446ce046 <d90d73ad183566c81320d453a223f610a280f210; version=47a049b38f567a2fbec76bc211ad7ad735519607; version=6.11; version=cb24bdcdecba1c60169efb74d88900888df59907 <1b3ff4d88b508b73e2bbddb59356311efb7ba192; version=e255683c06df572ead96db5efb5d21be30c0efaa <4d480efd98e290c445f4ba476e4dcda5624b1aab; version=e255683c06df572ead96db5efb5d21be30c0efaa <7c1d221e475e3d8eb8ed4702392d43f8c5134d1f; version=e255683c06df572ead96db5efb5d21be30c0efaa <7e4d88e36e5d0b8ffda637999cbca64c81701a81; version=e255683c06df572ead96db5efb5d21be30c0efaa <d191101dee25567c2af3b28565f45346c33d65f5

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Canonical UbuntuCVSS: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-667Improper Locking
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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