CVE-2026-98463

Freed-memory access via deferred scheduler reenqueues

Published Oct 18, 2026 · Updated Oct 18, 2026

Use-after-free in Linux sched_ext allows attackers to trigger stale kernel-memory dereferences through task reenqueues. enqueue_task_scx() derives SCX_RQ_IN_WAKEUP from merged flags, incorrectly suppressing deferred work for cross-CPU activation. An active BPF scheduler and a pending IMMED reenqueue surviving scheduler shutdown are required; the next scheduler dereferences freed per-CPU storage, but attacker privileges and resulting crash behavior are unspecified.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux sched_ext allows attackers to trigger stale kernel-memory dereferences through task reenqueues. enqueue_task_scx() derives SCX_RQ_IN_WAKEUP from merged flags, incorrectly suppressing deferred work for cross-CPU activation. An active BPF scheduler and a pending IMMED reenqueue surviving scheduler shutdown are required; the next scheduler dereferences freed per-CPU storage, but attacker privileges and resulting crash behavior are unspecified.

The record

CVE
CVE-2026-98463
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 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=57ccf5ccdc56954f2a91a7f66684fd31c566bde5 <3fdf2ceb31e8aff77451e468bc8409e10587916a
  2. Affected versionversion=57ccf5ccdc56954f2a91a7f66684fd31c566bde5 <df5cdc2c832ca4e8a6d774596b9005558761a403
  3. Affected versionversion=6.18.19 <6.18.55
  4. Affected versionversion=6.19.9 <6.20
  5. Affected versionversion=7.0
  6. Affected versionversion=997967adf10ce26c3e7bd89598b3ded62b943052 <6c401ae426e20e53a3398a8e79afd0964c0f5110
  7. Affected versionversion=ee502c056c4c9cce4c132ccb588e06ffe5b831c1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=57ccf5ccdc56954f2a91a7f66684fd31c566bde5 <3fdf2ceb31e8aff77451e468bc8409e10587916a; version=57ccf5ccdc56954f2a91a7f66684fd31c566bde5 <df5cdc2c832ca4e8a6d774596b9005558761a403; version=6.18.19 <6.18.55; version=6.19.9 <6.20; version=7.0; version=997967adf10ce26c3e7bd89598b3ded62b943052 <6c401ae426e20e53a3398a8e79afd0964c0f5110; version=ee502c056c4c9cce4c132ccb588e06ffe5b831c1

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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