CVE-2024-56661

Kernel crash via cleared TIPC socket dereference

Published Dec 27, 2024 · Updated May 11, 2026

NULL pointer dereference in Linux TIPC UDP bearer cleanup allows local users with low privileges to crash an affected kernel. The cleanup_bearer function reads ub->ubsock->sk after the socket pointer has become NULL and passes it through sock_net while decrementing wq_count. Reaching the faulty cleanup path requires local low-privileged access and a TIPC UDP bearer; the resulting kernel fault interrupts system availability.

CVSS severity5.5
Medium
EPSS probability0.22%
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 Linux TIPC UDP bearer cleanup allows local users with low privileges to crash an affected kernel. The cleanup_bearer function reads ub->ubsock->sk after the socket pointer has become NULL and passes it through sock_net while decrementing wq_count. Reaching the faulty cleanup path requires local low-privileged access and a TIPC UDP bearer; the resulting kernel fault interrupts system availability.

The record

CVE
CVE-2024-56661
Published
Dec 27, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 27, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=4e69457f9dfae67435f3ccf29008768eae860415 <d1d4dfb189a115734bff81c411bc58d9e348db7d
  2. Affected versionversion=5.10.231 <5.10.232
  3. Affected versionversion=5.15.174 <5.15.175
  4. Affected versionversion=5.4.287 <5.4.288
  5. Affected versionversion=6.1.120 <6.1.121
  6. Affected versionversion=6.12.5 <6.12.6
  7. Affected versionversion=650ee9a22d7a2de8999fac2d45983597a0c22359 <a771f349c95d3397636861a0a6462d4a7a7ecb25
  8. Affected versionversion=6.6.66 <6.6.67
  9. Affected versionversion=6a2fa13312e51a621f652d522d7e2df7066330b6 <b04d86fff66b15c07505d226431f808c15b1703c
  10. Affected versionversion=d00d4470bf8c4282617a3a10e76b20a9c7e4cffa <89ecda492d0a37fd00aaffc4151f1f44c26d93ac
  11. Affected versionversion=d2a4894f238551eae178904e7f45af87577074fd <07b569eda6fe6a1e83be5a587abee12d1303f95e
  12. Affected versionversion=d62d5180c036eeac09f80660edc7a602b369125f <754ec823ee53422361da7958a8c8bf3275426912
  13. Affected versionversion=e48b211c4c59062cb6dd6c2c37c51a7cc235a464 <a852c82eda4991e21610837aaa160965be71f5cc

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4e69457f9dfae67435f3ccf29008768eae860415 <d1d4dfb189a115734bff81c411bc58d9e348db7d; version=5.10.231 <5.10.232; version=5.15.174 <5.15.175; version=5.4.287 <5.4.288; version=6.1.120 <6.1.121; version=6.12.5 <6.12.6; version=650ee9a22d7a2de8999fac2d45983597a0c22359 <a771f349c95d3397636861a0a6462d4a7a7ecb25; version=6.6.66 <6.6.67; version=6a2fa13312e51a621f652d522d7e2df7066330b6 <b04d86fff66b15c07505d226431f808c15b1703c; version=d00d4470bf8c4282617a3a10e76b20a9c7e4cffa <89ecda492d0a37fd00aaffc4151f1f44c26d93ac; version=d2a4894f238551eae178904e7f45af87577074fd <07b569eda6fe6a1e83be5a587abee12d1303f95e; version=d62d5180c036eeac09f80660edc7a602b369125f <754ec823ee53422361da7958a8c8bf3275426912; version=e48b211c4c59062cb6dd6c2c37c51a7cc235a464 <a852c82eda4991e21610837aaa160965be71f5cc

Published CVSS scores

5.5CISA-ADPCVSS: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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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