CVE-2026-89928

Slab use-after-free via unlocked rmap walk

Published Sep 16, 2026 · Updated Sep 16, 2026

A use-after-free in the KVM x86 MMU in Linux 6.15 allows attackers to access freed slab memory during concurrent rmap operations. kvm_rmap_age_gfn_range re-reads an initially empty rmap after its lock is elided, allowing a writer to free the newly walked descriptor chain. The condition requires x86 KVM with lockless MMU aging and a race between rmap population and removal; no external trigger or further consequence is documented.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A use-after-free in the KVM x86 MMU in Linux 6.15 allows attackers to access freed slab memory during concurrent rmap operations. kvm_rmap_age_gfn_range re-reads an initially empty rmap after its lock is elided, allowing a writer to free the newly walked descriptor chain. The condition requires x86 KVM with lockless MMU aging and a race between rmap population and removal; no external trigger or further consequence is documented.

The record

CVE
CVE-2026-89928
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=6.15
  2. Affected versionversion=af3b6a9eba48419732b07a0472db7160282f0f39 <41debfc98526c0a95c41a62435aca0a70340a26d
  3. Affected versionversion=af3b6a9eba48419732b07a0472db7160282f0f39 <8edb3c09e43f7cd8a5dfd291c6e0fc9c74d4621d
  4. Affected versionversion=af3b6a9eba48419732b07a0472db7160282f0f39 <e428f9779a43737d830111238816f1928b07aefb

What conditions does exploitation require?

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

What is affected?

The Linux Kernel Organization · Linuxversion=6.15; version=af3b6a9eba48419732b07a0472db7160282f0f39 <41debfc98526c0a95c41a62435aca0a70340a26d; version=af3b6a9eba48419732b07a0472db7160282f0f39 <8edb3c09e43f7cd8a5dfd291c6e0fc9c74d4621d; version=af3b6a9eba48419732b07a0472db7160282f0f39 <e428f9779a43737d830111238816f1928b07aefb

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.

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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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