CVE-2023-53296

Kernel crash via stale SCTP send-stream index

Published Sep 16, 2025 · Updated Sep 16, 2025

NULL pointer dereference in Linux 4.15 through 6.3-rc5 allows local users to crash the kernel through concurrent SCTP sends. After wait_for_sndbuf wakes, sctp_sendmsg_to_asoc uses a stream index validated before INIT_ACK shrank the association's outbound stream count, dereferencing a missing stream. The race requires a local low-privileged process to send on stream N-1 while connection negotiation reduces the count to N-2; the resulting dereference interrupts the host.

CVSS severity5.5
Medium
EPSS probability0.14%
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 4.15 through 6.3-rc5 allows local users to crash the kernel through concurrent SCTP sends. After wait_for_sndbuf wakes, sctp_sendmsg_to_asoc uses a stream index validated before INIT_ACK shrank the association's outbound stream count, dereferencing a missing stream. The race requires a local low-privileged process to send on stream N-1 while connection negotiation reduces the count to N-2; the resulting dereference interrupts the host.

The record

CVE
CVE-2023-53296
Published
Sep 16, 2025
Updated
Sep 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2025Record 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=4.15
  2. Affected versionversion=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <0443fff49d6352160c200064156c25898bd9f58c
  3. Affected versionversion=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <2584024b23552c00d95b50255e47bd18d306d31a
  4. Affected versionversion=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <667eb99cf7c15fe5b0ecefe75cf658e20ef20c9f
  5. Affected versionversion=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <9346a1a21142357972a6f466ba6275ddc54b04ac
  6. Affected versionversion=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <a615e7270318fa0b98bf1ff38daf6cf52d840312
  7. Affected versionversion=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <b4b6dfad41aaae9e36e44327b18d5cf4b20dd2ce
  8. Affected versionversion=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <d2128636b303aa9cf065055402ee6697409a8837

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.15; version=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <0443fff49d6352160c200064156c25898bd9f58c; version=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <2584024b23552c00d95b50255e47bd18d306d31a; version=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <667eb99cf7c15fe5b0ecefe75cf658e20ef20c9f; version=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <9346a1a21142357972a6f466ba6275ddc54b04ac; version=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <a615e7270318fa0b98bf1ff38daf6cf52d840312; version=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <b4b6dfad41aaae9e36e44327b18d5cf4b20dd2ce; version=5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <d2128636b303aa9cf065055402ee6697409a8837

Published CVSS scores

5.5CISA-ADPCVSS: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

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-476NULL Pointer Dereference
T1499.004Application 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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