CVE-2025-23145Network attack vector

Kernel crash via concurrent MPTCP SYN-ACK handling

Published May 1, 2025 · Updated Aug 5, 2026

NULL pointer dereference in the Linux kernel MPTCP subsystem allows remote attackers to crash the kernel via duplicate SYN-ACK processing. In subflow_syn_recv_sock, two CPUs can process the same request after the first path transfers subflow_req->msk ownership and clears it; the second path passes NULL to mptcp_can_accept_new_subflow. Reachability requires an MPTCP listener and a repeated MP_JOIN acknowledgment, and successful triggering causes a kernel panic rather than data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux kernel MPTCP subsystem allows remote attackers to crash the kernel via duplicate SYN-ACK processing. In subflow_syn_recv_sock, two CPUs can process the same request after the first path transfers subflow_req->msk ownership and clears it; the second path passes NULL to mptcp_can_accept_new_subflow. Reachability requires an MPTCP listener and a repeated MP_JOIN acknowledgment, and successful triggering causes a kernel panic rather than data disclosure or modification.

The record

CVE
CVE-2025-23145
Published
May 1, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=5.9
  2. Affected versionversion=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <443041deb5ef6a1289a99ed95015ec7442f141dc
  3. Affected versionversion=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <4b2649b9717678aeb097893cc49f59311a1ecab0
  4. Affected versionversion=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <7f9ae060ed64aef8f174c5f1ea513825b1be9af1
  5. Affected versionversion=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <855bf0aacd51fced11ea9aa0d5101ee0febaeadb
  6. Affected versionversion=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <8cf7fef1bb2ffea7792bcbf71ca00216cecc725d
  7. Affected versionversion=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <b3088bd2a6790c8efff139d86d7a9d0b1305977b
  8. Affected versionversion=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <dc81e41a307df523072186b241fa8244fecd7803
  9. Affected versionversion=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <efd58a8dd9e7a709a90ee486a4247c923d27296f

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.9; version=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <443041deb5ef6a1289a99ed95015ec7442f141dc; version=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <4b2649b9717678aeb097893cc49f59311a1ecab0; version=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <7f9ae060ed64aef8f174c5f1ea513825b1be9af1; version=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <855bf0aacd51fced11ea9aa0d5101ee0febaeadb; version=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <8cf7fef1bb2ffea7792bcbf71ca00216cecc725d; version=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <b3088bd2a6790c8efff139d86d7a9d0b1305977b; version=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <dc81e41a307df523072186b241fa8244fecd7803; version=9466a1ccebbe54ac57fb8a89c2b4b854826546a8 <efd58a8dd9e7a709a90ee486a4247c923d27296f

Published CVSS scores

7.5LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS: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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1498Network 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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