CVE-2025-21733

Tracing disruption via stale tracepoint registration

Published Feb 27, 2025 · Updated May 11, 2026

Denial of service in Linux kernel tracing allows local users to interrupt tracing through a crafted timerlat option sequence. The removal path consults the current OSNOISE_WORKLOAD option instead of retained registration state, leaving tracepoints enabled and registering them twice when timerlat restarts. Reaching the fault requires local write access to tracing controls and the documented option sequence; the demonstrated result is a tracepoint warning and impaired tracing availability.

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

Denial of service in Linux kernel tracing allows local users to interrupt tracing through a crafted timerlat option sequence. The removal path consults the current OSNOISE_WORKLOAD option instead of retained registration state, leaving tracepoints enabled and registering them twice when timerlat restarts. Reaching the fault requires local write access to tracing controls and the documented option sequence; the demonstrated result is a tracepoint warning and impaired tracing availability.

The record

CVE
CVE-2025-21733
Published
Feb 27, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 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=6.5
  2. Affected versionversion=e88ed227f639ebcb31ed4e5b88756b47d904584b <b45707c3c0671d9c49fa7b94c197a508aa55d16f
  3. Affected versionversion=e88ed227f639ebcb31ed4e5b88756b47d904584b <e3ff4245928f948f3eb2e852aa350b870421c358
  4. Affected versionversion=e88ed227f639ebcb31ed4e5b88756b47d904584b <e482cecd2305be1e3e6a8ee70c9b86c511484f7b
  5. Affected versionversion=e88ed227f639ebcb31ed4e5b88756b47d904584b <ee8c4c39a8f97467d63adfe03bcd45139d8c8b53

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.5; version=e88ed227f639ebcb31ed4e5b88756b47d904584b <b45707c3c0671d9c49fa7b94c197a508aa55d16f; version=e88ed227f639ebcb31ed4e5b88756b47d904584b <e3ff4245928f948f3eb2e852aa350b870421c358; version=e88ed227f639ebcb31ed4e5b88756b47d904584b <e482cecd2305be1e3e6a8ee70c9b86c511484f7b; version=e88ed227f639ebcb31ed4e5b88756b47d904584b <ee8c4c39a8f97467d63adfe03bcd45139d8c8b53

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

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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