CVE-2026-98644Hinoki check available

CPU soft lockup via unyielding batch traversal

Published Oct 18, 2026 · Updated Oct 18, 2026

Missing rescheduling in Linux BPF hash-map batch operations allows local users to trigger CPU soft lockups through batch lookups. In __htab_map_lookup_and_delete_batch(), the batch count limits copied entries rather than visited buckets, while consecutive empty buckets retain an uninterrupted RCU critical section. Reachability requires access to a suitable BPF map; large sparse maps expose prolonged CPU stalls, demonstrated on CONFIG_PREEMPT_NONE kernels, rather than a documented permanent hang or data compromise.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Missing rescheduling in Linux BPF hash-map batch operations allows local users to trigger CPU soft lockups through batch lookups. In __htab_map_lookup_and_delete_batch(), the batch count limits copied entries rather than visited buckets, while consecutive empty buckets retain an uninterrupted RCU critical section. Reachability requires access to a suitable BPF map; large sparse maps expose prolonged CPU stalls, demonstrated on CONFIG_PREEMPT_NONE kernels, rather than a documented permanent hang or data compromise.

The record

CVE
CVE-2026-98644
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.001
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=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <44f9bcb5ab2b268bc763ed3ebec83308b4972936
  2. Affected versionversion=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <4e48fe9b1c77966bede0a73feb3059d7595f642d
  3. Affected versionversion=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <5c8b1869cb99a32a962388848cd19604fb41263e
  4. Affected versionversion=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <77a3b52b4455e6377e549539e757bc55eedefb51
  5. Affected versionversion=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <85136bf22404474a815fc0ed26ec0d1cbc1bc3f9
  6. Affected versionversion=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <ca5bd55fc508fbb5c08c62206d02237a5b6fc7e8
  7. Affected versionversion=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <f0c09de08ec077098b7e1563f2285f1c136cd816
  8. Affected versionversion=5.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <44f9bcb5ab2b268bc763ed3ebec83308b4972936; version=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <4e48fe9b1c77966bede0a73feb3059d7595f642d; version=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <5c8b1869cb99a32a962388848cd19604fb41263e; version=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <77a3b52b4455e6377e549539e757bc55eedefb51; version=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <85136bf22404474a815fc0ed26ec0d1cbc1bc3f9; version=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <ca5bd55fc508fbb5c08c62206d02237a5b6fc7e8; version=057996380a42bb64ccc04383cfa9c0ace4ea11f0 <f0c09de08ec077098b7e1563f2285f1c136cd816; version=5.6

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.

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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

T1499.001OS Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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