CVE-2026-99063Public exploit

Kernel-memory disclosure via unchecked ioctl result offset

Published Oct 23, 2026 · Updated Oct 23, 2026

Out-of-bounds read in Linux device-mapper allows local users with root privileges to read kernel memory via DM_LIST_DEVICES. In get_result_buffer(), data_start exceeds a minimum-size 305-byte buffer, causing ctl_ioctl() to copy seven adjacent bytes to userspace. Root access is required, and upstream explicitly states that this restriction makes the defect non-security-related.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Nov 1, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux device-mapper allows local users with root privileges to read kernel memory via DM_LIST_DEVICES. In get_result_buffer(), data_start exceeds a minimum-size 305-byte buffer, causing ctl_ioctl() to copy seven adjacent bytes to userspace. Root access is required, and upstream explicitly states that this restriction makes the defect non-security-related.

The record

CVE
CVE-2026-99063
Published
Oct 23, 2026
Updated
Oct 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 23, 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=2.6.25
  2. Affected versionversion=76c072b48e39e9291fbf02d6c912cf27d65e093d <5680b6fb3054677d4ee65d3baba24b649f1b430e
  3. Affected versionversion=76c072b48e39e9291fbf02d6c912cf27d65e093d <725b49c689bbb29ef740b0d6b5ea9390baa9a695
  4. Affected versionversion=76c072b48e39e9291fbf02d6c912cf27d65e093d <98195e822343a656b92e235847ab3e72b1a3f920
  5. Affected versionversion=76c072b48e39e9291fbf02d6c912cf27d65e093d <9b3fcf519d370df94a56f3b272d9eddffffa5be8
  6. Affected versionversion=76c072b48e39e9291fbf02d6c912cf27d65e093d <e5c3f3d8935ecc64c962fb66e6a86dbf79218f61

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.25; version=76c072b48e39e9291fbf02d6c912cf27d65e093d <5680b6fb3054677d4ee65d3baba24b649f1b430e; version=76c072b48e39e9291fbf02d6c912cf27d65e093d <725b49c689bbb29ef740b0d6b5ea9390baa9a695; version=76c072b48e39e9291fbf02d6c912cf27d65e093d <98195e822343a656b92e235847ab3e72b1a3f920; version=76c072b48e39e9291fbf02d6c912cf27d65e093d <9b3fcf519d370df94a56f3b272d9eddffffa5be8; version=76c072b48e39e9291fbf02d6c912cf27d65e093d <e5c3f3d8935ecc64c962fb66e6a86dbf79218f61

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

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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