CVE-2026-89899Public exploitHinoki check available

Local service interruption via delayed-work use-after-free

Published Sep 16, 2026 · Updated Sep 16, 2026

Use-after-free in the Linux kernel CEC core allows local users to interrupt service by signaling a blocking CEC transmit. In cec_transmit_msg_fh(), cancel_delayed_work_sync() can finish before cec_transmit_done_ts() schedules the reply timeout, leaving delayed work armed after its data is freed. Reaching the race requires access to a CEC device, a blocking transmit, and a signal during the killable wait; the demonstrated consequence is a kernel warning and denial of service.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Use-after-free in the Linux kernel CEC core allows local users to interrupt service by signaling a blocking CEC transmit. In cec_transmit_msg_fh(), cancel_delayed_work_sync() can finish before cec_transmit_done_ts() schedules the reply timeout, leaving delayed work armed after its data is freed. Reaching the race requires access to a CEC device, a blocking transmit, and a signal during the killable wait; the demonstrated consequence is a kernel warning and denial of service.

The record

CVE
CVE-2026-89899
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=2781b86d7e45de09befa5ace296b66787146561f
  2. Affected versionversion=4.18.19 <4.19
  3. Affected versionversion=4.19.2 <4.20
  4. Affected versionversion=4.20
  5. Affected versionversion=490d84f6d73c12f4204241cff8651eed60aae914 <0fbd5c2327020858c45b2d1c65775d64cdeca523
  6. Affected versionversion=490d84f6d73c12f4204241cff8651eed60aae914 <9a951931d4b4084acd64fa55fc3672a9da45ddf9
  7. Affected versionversion=490d84f6d73c12f4204241cff8651eed60aae914 <9c6ceb0949227c1f0cf0e19393daec72d9889871
  8. Affected versionversion=490d84f6d73c12f4204241cff8651eed60aae914 <a3adb63b121937b97f7fdc51e96564c7c799538b
  9. Affected versionversion=e448dfd6d3ec944411f6575bc24e4f8baa1e297f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=2781b86d7e45de09befa5ace296b66787146561f; version=4.18.19 <4.19; version=4.19.2 <4.20; version=4.20; version=490d84f6d73c12f4204241cff8651eed60aae914 <0fbd5c2327020858c45b2d1c65775d64cdeca523; version=490d84f6d73c12f4204241cff8651eed60aae914 <9a951931d4b4084acd64fa55fc3672a9da45ddf9; version=490d84f6d73c12f4204241cff8651eed60aae914 <9c6ceb0949227c1f0cf0e19393daec72d9889871; version=490d84f6d73c12f4204241cff8651eed60aae914 <a3adb63b121937b97f7fdc51e96564c7c799538b; version=e448dfd6d3ec944411f6575bc24e4f8baa1e297f

Published CVSS scores

No CVSS assessment is available in this record.

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

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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