CVE-2026-98868

Kernel crash via unchecked cache-metadata size

Published Oct 18, 2026 · Updated Oct 18, 2026

Metadata validation failure in Linux dm-pcache allows local users to crash the kernel via a forged cache-device key count. cache_replay() and the writeback and garbage-collection workers advance past a segment when key_num makes the calculated kset size exceed its remaining space, triggering cache_pos_advance() BUG_ON. Exploitation requires dm-pcache to consume attacker-controlled cache metadata; supplying the cache device during table loading requires CAP_SYS_ADMIN.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Metadata validation failure in Linux dm-pcache allows local users to crash the kernel via a forged cache-device key count. cache_replay() and the writeback and garbage-collection workers advance past a segment when key_num makes the calculated kset size exceed its remaining space, triggering cache_pos_advance() BUG_ON. Exploitation requires dm-pcache to consume attacker-controlled cache metadata; supplying the cache device during table loading requires CAP_SYS_ADMIN.

The record

CVE
CVE-2026-98868
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

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=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <01a700e9278da5706c865b9ca3ae70fdb7b4531d
  2. Affected versionversion=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb
  3. Affected versionversion=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <96e2863b1f81ea61b8d8d5d5a45d3b4c018f8e10
  4. Affected versionversion=6.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <01a700e9278da5706c865b9ca3ae70fdb7b4531d; version=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb; version=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <96e2863b1f81ea61b8d8d5d5a45d3b4c018f8e10; version=6.18

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
Privilegesadmin
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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