CVE-2026-64058

Local kernel memory corruption via netfs writeback race

Published Jul 19, 2026 · Updated Jul 19, 2026

Use-after-free in Linux Kernel release lines from 6.12 allows local users to crash the kernel via concurrent netfs file I/O. netfs_read_folio() tests the folio dirty flag and follows folio->private without first waiting for writeback, allowing the collector to free the attached netfs_folio before netfs_read_gaps() dereferences it. Unprivileged read and write access to an already-mounted CIFS, Ceph, AFS, 9p, or NFS-with-cache filesystem is sufficient; stale metadata can expose kernel heap data, corrupt page-cache I/O, or trigger an oops or panic.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux Kernel release lines from 6.12 allows local users to crash the kernel via concurrent netfs file I/O. netfs_read_folio() tests the folio dirty flag and follows folio->private without first waiting for writeback, allowing the collector to free the attached netfs_folio before netfs_read_gaps() dereferences it. Unprivileged read and write access to an already-mounted CIFS, Ceph, AFS, 9p, or NFS-with-cache filesystem is sufficient; stale metadata can expose kernel heap data, corrupt page-cache I/O, or trigger an oops or panic.

The record

CVE
CVE-2026-64058
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

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=6.12
  2. Affected versionversion=ee4cdf7ba857a894ad1650d6ab77669cbbfa329e <b8271cccdd5e43cc8d738afb8b51f6ad05b1cb4b
  3. Affected versionversion=ee4cdf7ba857a894ad1650d6ab77669cbbfa329e <ded0c6f1606061148c202825f7e53d711f9f84cf
  4. Affected versionversion=ee4cdf7ba857a894ad1650d6ab77669cbbfa329e <f17b9121bb99f88188ec9be2db5da1d561f4c01b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.12; version=ee4cdf7ba857a894ad1650d6ab77669cbbfa329e <b8271cccdd5e43cc8d738afb8b51f6ad05b1cb4b; version=ee4cdf7ba857a894ad1650d6ab77669cbbfa329e <ded0c6f1606061148c202825f7e53d711f9f84cf; version=ee4cdf7ba857a894ad1650d6ab77669cbbfa329e <f17b9121bb99f88188ec9be2db5da1d561f4c01b

Published CVSS scores

7.8Linux Kernel CVE TeamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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