CVE-2025-40187Network attack vector

Remote host crash via SCTP null dereference

Published Nov 12, 2025 · Updated Aug 5, 2026

Null pointer dereference in the Linux kernel SCTP COOKIE ECHO handler allows remote attackers to crash the host through a crafted handshake. The sctp_sf_do_5_1D_ce function can leave ai_ev null when a peer omits adaptation and authentication parameters and an atomic event allocation fails, then passes that pointer to sctp_ulpevent_free. A listening SCTP socket must process the unauthenticated handshake; the resulting kernel fault causes a panic or disables packet processing, depending on panic policy.

CVSS severity7.5
High
EPSS probability0.60%
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 SCTP COOKIE ECHO handler allows remote attackers to crash the host through a crafted handshake. The sctp_sf_do_5_1D_ce function can leave ai_ev null when a peer omits adaptation and authentication parameters and an atomic event allocation fails, then passes that pointer to sctp_ulpevent_free. A listening SCTP socket must process the unauthenticated handshake; the resulting kernel fault causes a panic or disables packet processing, depending on panic policy.

The record

CVE
CVE-2025-40187
Published
Nov 12, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 12, 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=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <025419f4e216a3ae0d0cec622262e98e8078c447
  2. Affected versionversion=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <1014b83778c8677f1d7a57c26dc728baa801ac62
  3. Affected versionversion=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <2f3119686ef50319490ccaec81a575973da98815
  4. Affected versionversion=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <7f702f85df0266ed7b5bab81ba50394c92f3c928
  5. Affected versionversion=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <badbd79313e6591616c1b78e29a9b71efed7f035
  6. Affected versionversion=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <c21f45cfa4a9526b34d76b397c9ef080668b6e73
  7. Affected versionversion=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <d0e8f1445c19b1786759ba72a38267e1449bab7e
  8. Affected versionversion=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <dbceedc0213e75bf3e9f9f9e2f66b10699d004fe
  9. Affected versionversion=4.17

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <025419f4e216a3ae0d0cec622262e98e8078c447; version=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <1014b83778c8677f1d7a57c26dc728baa801ac62; version=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <2f3119686ef50319490ccaec81a575973da98815; version=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <7f702f85df0266ed7b5bab81ba50394c92f3c928; version=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <badbd79313e6591616c1b78e29a9b71efed7f035; version=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <c21f45cfa4a9526b34d76b397c9ef080668b6e73; version=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <d0e8f1445c19b1786759ba72a38267e1449bab7e; version=30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b <dbceedc0213e75bf3e9f9f9e2f66b10699d004fe; version=4.17

Published CVSS scores

4.7OracleCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
4.1SUSECVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
7.5LinuxCVSS:3.1/AV:N/AC:L/PR:N/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

T1499.004Endpoint Denial of Service: Application or System Exploitation

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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