CVE-2025-39729

Kernel crash via nullable SEV error dereference

Published Sep 7, 2025 · Updated Jul 24, 2026

Uninitialized pointer access in Linux kernel 6.16 allows local users to crash the system during AMD SEV platform initialization. The __sev_platform_init_locked function passes a nullable caller error pointer to the DF_FLUSH command and dereferences it for logging when that command fails. Reachability requires local access to SEV platform initialization on an AMD SEV-capable host and a failing DF_FLUSH command; the bounded impact is a kernel crash.

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

Uninitialized pointer access in Linux kernel 6.16 allows local users to crash the system during AMD SEV platform initialization. The __sev_platform_init_locked function passes a nullable caller error pointer to the DF_FLUSH command and dereferences it for logging when that command fails. Reachability requires local access to SEV platform initialization on an AMD SEV-capable host and a failing DF_FLUSH command; the bounded impact is a kernel crash.

The record

CVE
CVE-2025-39729
Published
Sep 7, 2025
Updated
Jul 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-824, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 24, 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=6.16
  2. Affected versionversion=9770b428b1a28360663f1f5e524ee458b4cf454b <0fa766726c091ff0ec7d26874f6e4724d23ecb0e
  3. Affected versionversion=9770b428b1a28360663f1f5e524ee458b4cf454b <841634e1fdc2bdf35ab851fc279fd3bedcdf5e93
  4. Affected versionversion=e6bef2d0dfa036afc32df982240d0368b17ee7fd <26eb4fceaf8cad2b92255baf7f185b0a1e3f070c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.16; version=9770b428b1a28360663f1f5e524ee458b4cf454b <0fa766726c091ff0ec7d26874f6e4724d23ecb0e; version=9770b428b1a28360663f1f5e524ee458b4cf454b <841634e1fdc2bdf35ab851fc279fd3bedcdf5e93; version=e6bef2d0dfa036afc32df982240d0368b17ee7fd <26eb4fceaf8cad2b92255baf7f185b0a1e3f070c

Published CVSS scores

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-824Access of Uninitialized Pointer
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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