CVE-2024-26903

Kernel crash via late HCI response

Published Apr 17, 2024 · Updated May 12, 2026

Null pointer dereference in Linux kernel RFCOMM before 6.8 allows local users to crash the system through a delayed HCI response. The RFCOMM receive path calls rfcomm_check_security after RFCOMM and L2CAP teardown, then dereferences conn->hcon after the L2CAP connection pointer has been released. Reachability requires low-privileged local access and a late Encryption Key Size response while HCI remains connected; the documented consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.28%
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 kernel RFCOMM before 6.8 allows local users to crash the system through a delayed HCI response. The RFCOMM receive path calls rfcomm_check_security after RFCOMM and L2CAP teardown, then dereferences conn->hcon after the L2CAP connection pointer has been released. Reachability requires low-privileged local access and a late Encryption Key Size response while HCI remains connected; the documented consequence is a kernel crash.

The record

CVE
CVE-2024-26903
Published
Apr 17, 2024
Updated
May 12, 2026
Vendor
Siemens
Product
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 17, 2024CVE publishedPublication date reported by the CVE source.
  2. May 12, 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=0 <*

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2535b848fa0f42ddff3e5255cf5e742c9b77bb26; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <369f419c097e82407dd429a202cde9a73d3ae29b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3ead59bafad05f2967ae2438c0528d53244cfde5; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <567c0411dc3b424fc7bd1e6109726d7ba32d4f73; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5f369efd9d963c1f711a06c9b8baf9f5ce616d85; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5f9fe302dd3a9bbc50f4888464c1773f45166bfd; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <81d7d920a22fd58ef9aedb1bd0a68ee32bd23e96; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8d1753973f598531baaa2c1033cf7f7b5bb004b0; version=2.6.12

Published CVSS scores

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.

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Technologies

Your stack

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Your stack

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