CVE-2025-39865

Kernel crash via unchecked TEE shared-memory pointer

Published Sep 19, 2025 · Updated Sep 19, 2025

NULL pointer dereference in Linux TEE shared-memory code allows local users to crash the kernel during shutdown or hibernation. The tee_shm_put function dereferences a shared-memory pointer returned as NULL by reg_pair_to_ptr after __optee_disable_shm_cache passes it through tee_shm_free without validation. The published record does not identify attacker-controlled input; reachability depends on an OP-TEE configuration and a shutdown or hibernation path, and the documented consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.16%
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 TEE shared-memory code allows local users to crash the kernel during shutdown or hibernation. The tee_shm_put function dereferences a shared-memory pointer returned as NULL by reg_pair_to_ptr after __optee_disable_shm_cache passes it through tee_shm_free without validation. The published record does not identify attacker-controlled input; reachability depends on an OP-TEE configuration and a shutdown or hibernation path, and the documented consequence is a kernel crash.

The record

CVE
CVE-2025-39865
Published
Sep 19, 2025
Updated
Sep 19, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 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=3d556a28bbfe34a80b014db49908b0f1bcb1ae80
  2. Affected versionversion=492eb7afe858d60408b2da09adc78540c4d16543 <4377eac565c297fdfccd2f8e9bf94ee84ff6172f
  3. Affected versionversion=5.16
  4. Affected versionversion=940e68e57ab69248fabba5889e615305789db8a7
  5. Affected versionversion=b4a661b4212b8fac8853ec3b68e4a909dccc88a1
  6. Affected versionversion=c05d8f66ec3470e5212c4d08c46d6cb5738d600d <f266188603c34e6e234fb0dfc3185f0ba98d71b7
  7. Affected versionversion=dfd0743f1d9ea76931510ed150334d571fbab49d <25e315bc8ad363bd1194e49062f183ad4011957e
  8. Affected versionversion=dfd0743f1d9ea76931510ed150334d571fbab49d <5e07a4235bb85d9ef664411e4ff4ac34783c18ff
  9. Affected versionversion=dfd0743f1d9ea76931510ed150334d571fbab49d <963fca19fe34c496e04f7dd133b807b76a5434ca
  10. Affected versionversion=dfd0743f1d9ea76931510ed150334d571fbab49d <add1ecc8f3ad8df22e3599c5c88d7907cc2a3079
  11. Affected versionversion=dfd0743f1d9ea76931510ed150334d571fbab49d <e4a718a3a47e89805c3be9d46a84de1949a98d5d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3d556a28bbfe34a80b014db49908b0f1bcb1ae80; version=492eb7afe858d60408b2da09adc78540c4d16543 <4377eac565c297fdfccd2f8e9bf94ee84ff6172f; version=5.16; version=940e68e57ab69248fabba5889e615305789db8a7; version=b4a661b4212b8fac8853ec3b68e4a909dccc88a1; version=c05d8f66ec3470e5212c4d08c46d6cb5738d600d <f266188603c34e6e234fb0dfc3185f0ba98d71b7; version=dfd0743f1d9ea76931510ed150334d571fbab49d <25e315bc8ad363bd1194e49062f183ad4011957e; version=dfd0743f1d9ea76931510ed150334d571fbab49d <5e07a4235bb85d9ef664411e4ff4ac34783c18ff; version=dfd0743f1d9ea76931510ed150334d571fbab49d <963fca19fe34c496e04f7dd133b807b76a5434ca; version=dfd0743f1d9ea76931510ed150334d571fbab49d <add1ecc8f3ad8df22e3599c5c88d7907cc2a3079; version=dfd0743f1d9ea76931510ed150334d571fbab49d <e4a718a3a47e89805c3be9d46a84de1949a98d5d

Published CVSS scores

5.5Canonical UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS: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
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

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Your stack

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