CVE-2024-40910

Kernel crash via unbalanced AX.25 reference count

Published Jul 12, 2024 · Updated Aug 5, 2026

Denial of service in the Linux kernel AX.25 stack allows remote attackers to crash affected systems through inbound connections. The ax25_accept path omits netdev_hold() and ax25_dev_hold(), but ax25_release() still decrements both references, causing underflow. Exposure requires an AX.25 interface accepting connections from a shared radio channel or Ethernet segment; repeated sessions can crash the kernel or hang interface removal.

CVSS severity8.8
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux kernel AX.25 stack allows remote attackers to crash affected systems through inbound connections. The ax25_accept path omits netdev_hold() and ax25_dev_hold(), but ax25_release() still decrements both references, causing underflow. Exposure requires an AX.25 interface accepting connections from a shared radio channel or Ethernet segment; repeated sessions can crash the kernel or hang interface removal.

The record

CVE
CVE-2024-40910
Published
Jul 12, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-911, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 12, 2024CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.14.277 <4.15
  2. Affected versionversion=4.19.240 <4.20
  3. Affected versionversion=452ae92b99062d2f6a34324eaf705a3b7eac9f8b
  4. Affected versionversion=5.10.112 <5.11
  5. Affected versionversion=5.15.35 <5.16
  6. Affected versionversion=5.17.2 <5.18
  7. Affected versionversion=5.18
  8. Affected versionversion=534156dd4ed768e30a43de0036f45dca7c54818f
  9. Affected versionversion=5.4.190 <5.5
  10. Affected versionversion=9e1e088a57c23251f1cfe9601bbd90ade2ea73b9
  11. Affected versionversion=9fd75b66b8f68498454d685dc4ba13192ae069b0 <3c34fb0bd4a4237592c5ecb5b2e2531900c55774
  12. Affected versionversion=9fd75b66b8f68498454d685dc4ba13192ae069b0 <52100fd74ad07b53a4666feafff1cd11436362d3
  13. Affected versionversion=9fd75b66b8f68498454d685dc4ba13192ae069b0 <a723a6c8d4831cc8e2c7b0c9f3f0c010d4671964
  14. Affected versionversion=9fd75b66b8f68498454d685dc4ba13192ae069b0 <f4df9d6c8d4e4c818252b0419c2165d66eabd4eb
  15. Affected versionversion=b20a5ab0f5fb175750c6bafd4cf12daccf00c738
  16. Affected versionversion=c44a453ffe16eb08acdc6129ac4fa0192dbc0456
  17. Affected versionversion=de55a1338e6a48ff1e41ea8db1432496fbe2a62b

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.14.277 <4.15; version=4.19.240 <4.20; version=452ae92b99062d2f6a34324eaf705a3b7eac9f8b; version=5.10.112 <5.11; version=5.15.35 <5.16; version=5.17.2 <5.18; version=5.18; version=534156dd4ed768e30a43de0036f45dca7c54818f; version=5.4.190 <5.5; version=9e1e088a57c23251f1cfe9601bbd90ade2ea73b9; version=9fd75b66b8f68498454d685dc4ba13192ae069b0 <3c34fb0bd4a4237592c5ecb5b2e2531900c55774; version=9fd75b66b8f68498454d685dc4ba13192ae069b0 <52100fd74ad07b53a4666feafff1cd11436362d3; version=9fd75b66b8f68498454d685dc4ba13192ae069b0 <a723a6c8d4831cc8e2c7b0c9f3f0c010d4671964; version=9fd75b66b8f68498454d685dc4ba13192ae069b0 <f4df9d6c8d4e4c818252b0419c2165d66eabd4eb; version=b20a5ab0f5fb175750c6bafd4cf12daccf00c738; version=c44a453ffe16eb08acdc6129ac4fa0192dbc0456; version=de55a1338e6a48ff1e41ea8db1432496fbe2a62b

Published CVSS scores

8.8Linux CNACVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.5SUSECVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-911Improper Update of Reference Count
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

See the directory against your own environment.

Your stack

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