CVE-2025-37922

Kernel crash via shared unaligned altmap page

Published May 20, 2025 · Updated May 11, 2026

NULL pointer dereference in Linux kernel 6.6 allows local users to crash the kernel while removing an unaligned NVDIMM namespace. An unaligned section vmemmap start can make adjacent namespaces share an altmap page, which the earlier namespace later misclassifies and frees as RAM. Low-privileged local access and a PowerPC Book3S radix system with the affected namespace layout are required; triggering causes a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.19%
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 6.6 allows local users to crash the kernel while removing an unaligned NVDIMM namespace. An unaligned section vmemmap start can make adjacent namespaces share an altmap page, which the earlier namespace later misclassifies and frees as RAM. Low-privileged local access and a PowerPC Book3S radix system with the affected namespace layout are required; triggering causes a kernel crash.

The record

CVE
CVE-2025-37922
Published
May 20, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 20, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=368a0590d954a659b16ab945328ada0cc10f93a0 <400be767deaf31a073c6d14c5d151ae5ac2a60e2
  2. Affected versionversion=368a0590d954a659b16ab945328ada0cc10f93a0 <7f5476d80f2cb364701cd1fa138a14b241ca99e9
  3. Affected versionversion=368a0590d954a659b16ab945328ada0cc10f93a0 <9a8d4d7072d4df108479b1adc4b0840e96f6f61d
  4. Affected versionversion=368a0590d954a659b16ab945328ada0cc10f93a0 <9cf7e13fecbab0894f6986fc6986ab2eba8de52e
  5. Affected versionversion=6.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=368a0590d954a659b16ab945328ada0cc10f93a0 <400be767deaf31a073c6d14c5d151ae5ac2a60e2; version=368a0590d954a659b16ab945328ada0cc10f93a0 <7f5476d80f2cb364701cd1fa138a14b241ca99e9; version=368a0590d954a659b16ab945328ada0cc10f93a0 <9a8d4d7072d4df108479b1adc4b0840e96f6f61d; version=368a0590d954a659b16ab945328ada0cc10f93a0 <9cf7e13fecbab0894f6986fc6986ab2eba8de52e; version=6.6

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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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