CVE-2025-21894

Kernel crash via unsupported VF one-step timestamping

Published Apr 1, 2025 · Updated May 11, 2026

Denial of service in Linux kernel ENETC drivers from 5.3 allows local users to crash the kernel through one-step TX timestamping. The enetc_hwtstamp_set path accepts HWTSTAMP_TX_ONESTEP_SYNC for a virtual function, so transmit handling accesses PF-only PMa_SINGLE_STEP registers. Low-privileged local access to an ENETC virtual function and one-step timestamp configuration is required; successful triggering causes a kernel paging fault and host service interruption.

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

Denial of service in Linux kernel ENETC drivers from 5.3 allows local users to crash the kernel through one-step TX timestamping. The enetc_hwtstamp_set path accepts HWTSTAMP_TX_ONESTEP_SYNC for a virtual function, so transmit handling accesses PF-only PMa_SINGLE_STEP registers. Low-privileged local access to an ENETC virtual function and one-step timestamp configuration is required; successful triggering causes a kernel paging fault and host service interruption.

The record

CVE
CVE-2025-21894
Published
Apr 1, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 1, 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=41514737ecaa603a5127cdccdc5f17ef11b9b3dc <1748531839298ab7be682155f6cd98ae04773e6a
  2. Affected versionversion=41514737ecaa603a5127cdccdc5f17ef11b9b3dc <3d9634211121700568d0e3635ebdd5df06d20440
  3. Affected versionversion=41514737ecaa603a5127cdccdc5f17ef11b9b3dc <8c393efd7420cc994864d059fcc6219bfd7cb840
  4. Affected versionversion=41514737ecaa603a5127cdccdc5f17ef11b9b3dc <a562d0c4a893eae3ea51d512c4d90ab858a6b7ec
  5. Affected versionversion=5.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=41514737ecaa603a5127cdccdc5f17ef11b9b3dc <1748531839298ab7be682155f6cd98ae04773e6a; version=41514737ecaa603a5127cdccdc5f17ef11b9b3dc <3d9634211121700568d0e3635ebdd5df06d20440; version=41514737ecaa603a5127cdccdc5f17ef11b9b3dc <8c393efd7420cc994864d059fcc6219bfd7cb840; version=41514737ecaa603a5127cdccdc5f17ef11b9b3dc <a562d0c4a893eae3ea51d512c4d90ab858a6b7ec; version=5.3

Published CVSS scores

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

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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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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