CVE-2026-63953

Kernel memory leak via failed PMD check

Published Jul 19, 2026 · Updated Jul 19, 2026

Memory leak in Linux Kernel 6.19 allows attackers to consume kernel memory when a device-page migration PMD check fails. migrate_vma_insert_huge_pmd_page allocates a page table with pte_alloc_one but its unlock_abort error path does not free that allocation. Upstream material does not identify an attacker-controlled trigger or state whether repeated failures can interrupt service.

CVSS severityUnavailable
Unscored
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in Linux Kernel 6.19 allows attackers to consume kernel memory when a device-page migration PMD check fails. migrate_vma_insert_huge_pmd_page allocates a page table with pte_alloc_one but its unlock_abort error path does not free that allocation. Upstream material does not identify an attacker-controlled trigger or state whether repeated failures can interrupt service.

The record

CVE
CVE-2026-63953
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=6.19
  2. Affected versionversion=a30b48bf1b244f11bf9b6d20cdccfe0c2264130c <24861d04f197bb651e9dfb211978271c15f75a98
  3. Affected versionversion=a30b48bf1b244f11bf9b6d20cdccfe0c2264130c <2c6f81d58741349298f51ff697d988cb42881453

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.19; version=a30b48bf1b244f11bf9b6d20cdccfe0c2264130c <24861d04f197bb651e9dfb211978271c15f75a98; version=a30b48bf1b244f11bf9b6d20cdccfe0c2264130c <2c6f81d58741349298f51ff697d988cb42881453

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.

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

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
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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