CVE-2025-21840

Local intel-lpmd crash via shifted netlink attribute

Published Mar 7, 2025 · Updated May 11, 2026

Improper UAPI compatibility in Linux kernel 6.13 through 6.13.3 allows local users to crash intel-lpmd through thermal netlink events. In enum thermal_genl_attr, a new THERMAL_GENL_ATTR_TZ_PREV_TEMP member was inserted before existing members, renumbering THERMAL_GENL_ATTR_CPU_CAPABILITY while intel-lpmd continued interpreting its former raw value. Local low-privileged access and an Intel HFI setup using intel-lpmd are required; the reported consequence is a userspace daemon crash.

CVSS severity5.5
Medium
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

Improper UAPI compatibility in Linux kernel 6.13 through 6.13.3 allows local users to crash intel-lpmd through thermal netlink events. In enum thermal_genl_attr, a new THERMAL_GENL_ATTR_TZ_PREV_TEMP member was inserted before existing members, renumbering THERMAL_GENL_ATTR_CPU_CAPABILITY while intel-lpmd continued interpreting its former raw value. Local low-privileged access and an Intel HFI setup using intel-lpmd are required; the reported consequence is a userspace daemon crash.

The record

CVE
CVE-2025-21840
Published
Mar 7, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 7, 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=1773572863c43a14a3e45f0591f28b7dec1ee52a <3a4ca365c51729143a2cab693cd40fe0bb585ef0
  2. Affected versionversion=1773572863c43a14a3e45f0591f28b7dec1ee52a <c195b9c6ab9c383d7aa3f4a65879b3ca90cb378b
  3. Affected versionversion=6.13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1773572863c43a14a3e45f0591f28b7dec1ee52a <3a4ca365c51729143a2cab693cd40fe0bb585ef0; version=1773572863c43a14a3e45f0591f28b7dec1ee52a <c195b9c6ab9c383d7aa3f4a65879b3ca90cb378b; version=6.13

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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