CVE-2025-38696

Kernel crash via NULL ABI pointer dereference

Published Sep 4, 2025 · Updated May 23, 2026

NULL pointer dereference in the Linux kernel MIPS stack_top() path allows local users to crash the kernel through an ABI-less task. The function reads the task ABI pointer without first checking whether an ABI or vDSO mapping exists, so an ABI-less kernel thread reaches a NULL pointer. Reachability requires a MIPS build and an ABI-less or vDSO-less task to enter stack_top(); the consequence is a kernel crash, including on SIMATIC CN 4100 before V5.0.

CVSS severity5.5
Medium
EPSS probability0.18%
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 MIPS stack_top() path allows local users to crash the kernel through an ABI-less task. The function reads the task ABI pointer without first checking whether an ABI or vDSO mapping exists, so an ABI-less kernel thread reaches a NULL pointer. Reachability requires a MIPS build and an ABI-less or vDSO-less task to enter stack_top(); the consequence is a kernel crash, including on SIMATIC CN 4100 before V5.0.

The record

CVE
CVE-2025-38696
Published
Sep 4, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-20
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 4, 2025CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=4.14.77 <4.15
  2. Affected versionversion=4.18.15 <4.19
  3. Affected versionversion=4.19
  4. Affected versionversion=86717a97f9218de798c6d33e0014ab9325e18f56
  5. Affected versionversion=e4882348eaa9f5f052cb21d2a5aa99a063e4308b
  6. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <24d098b6f69b0aa806ffcb3e18259bee31650b28
  7. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <5b6839b572b503609b9b58bc6c04a816eefa0794
  8. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <82d140f6aab5e89a9d3972697a0dbe1498752d9b
  9. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <ab18e48a503230d675e824a0d68a108bdff42503
  10. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <bd90dbd196831f5c2620736dc221db2634cf1e8e
  11. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <cddf47d20b0325dc8a4e57b833fe96e8f36c42a4
  12. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <e78033e59444d257d095b73ce5d20625294f6ec2
  13. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <e9f4a6b3421e936c3ee9d74710243897d74dbaa2
  14. Affected versionversion=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <f22de2027b206ddfb8a075800bb5d0dacf2da4b8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.14.77 <4.15; version=4.18.15 <4.19; version=4.19; version=86717a97f9218de798c6d33e0014ab9325e18f56; version=e4882348eaa9f5f052cb21d2a5aa99a063e4308b; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <24d098b6f69b0aa806ffcb3e18259bee31650b28; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <5b6839b572b503609b9b58bc6c04a816eefa0794; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <82d140f6aab5e89a9d3972697a0dbe1498752d9b; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <ab18e48a503230d675e824a0d68a108bdff42503; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <bd90dbd196831f5c2620736dc221db2634cf1e8e; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <cddf47d20b0325dc8a4e57b833fe96e8f36c42a4; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <e78033e59444d257d095b73ce5d20625294f6ec2; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <e9f4a6b3421e936c3ee9d74710243897d74dbaa2; version=ea7e0480a4b695d0aa6b3fa99bd658a003122113 <f22de2027b206ddfb8a075800bb5d0dacf2da4b8
Siemens · SIMATIC CN 4100version=0 <V5.0

Published CVSS scores

5.5Siemens ProductCERTCVSS: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-20Improper Input Validation

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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