CVE-2025-21810

Kernel crash via uninitialized class device iterator

Published Feb 27, 2025 · Updated Aug 5, 2026

Wild-pointer dereference in affected Linux kernel releases allows local users to crash the kernel through class device iteration. When class_to_subsys fails, class_dev_iter_init returns without initializing the iterator, and subsequent next or exit calls dereference its wild members. The path requires local low-privileged access and an invalid class-to-subsystem lookup; the bounded operational consequence is a system crash.

CVSS severity7.8
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Wild-pointer dereference in affected Linux kernel releases allows local users to crash the kernel through class device iteration. When class_to_subsys fails, class_dev_iter_init returns without initializing the iterator, and subsequent next or exit calls dereference its wild members. The path requires local low-privileged access and an invalid class-to-subsystem lookup; the bounded operational consequence is a system crash.

The record

CVE
CVE-2025-21810
Published
Feb 27, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=6.4
  2. Affected versionversion=7b884b7f24b42fa25e92ed724ad82f137610afaf <1614e75d1a1b63db6421c7a4bf37004720c7376c
  3. Affected versionversion=7b884b7f24b42fa25e92ed724ad82f137610afaf <5c504e9767b947cf7d4e29b811c0c8b3c53242b7
  4. Affected versionversion=7b884b7f24b42fa25e92ed724ad82f137610afaf <e128f82f7006991c99a58114f70ef61e937b1ac1
  5. Affected versionversion=7b884b7f24b42fa25e92ed724ad82f137610afaf <f4b9bc823b0cfdebfed479c0e87d6939c7562e87

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.4; version=7b884b7f24b42fa25e92ed724ad82f137610afaf <1614e75d1a1b63db6421c7a4bf37004720c7376c; version=7b884b7f24b42fa25e92ed724ad82f137610afaf <5c504e9767b947cf7d4e29b811c0c8b3c53242b7; version=7b884b7f24b42fa25e92ed724ad82f137610afaf <e128f82f7006991c99a58114f70ef61e937b1ac1; version=7b884b7f24b42fa25e92ed724ad82f137610afaf <f4b9bc823b0cfdebfed479c0e87d6939c7562e87

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8Linux CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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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