CVE-2026-64160

Filesystem operation hang via torn netfs size fields

Published Jul 19, 2026 · Updated Jul 19, 2026

Race condition in the Linux Kernel netfs subsystem allows attackers to stall filesystem operations during concurrent network file-size updates. The netfs paths update 64-bit remote_i_size and zero_point values without consistent i_lock and shared i_size seqcount protection, permitting torn reads. The defect is specific to 32-bit builds; a corrupted i_size_seqcount can make later i_size_read calls spin indefinitely, interrupting affected 9p, AFS, or SMB filesystem work.

CVSS severity9.8
Critical
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux Kernel netfs subsystem allows attackers to stall filesystem operations during concurrent network file-size updates. The netfs paths update 64-bit remote_i_size and zero_point values without consistent i_lock and shared i_size seqcount protection, permitting torn reads. The defect is specific to 32-bit builds; a corrupted i_size_seqcount can make later i_size_read calls spin indefinitely, interrupting affected 9p, AFS, or SMB filesystem work.

The record

CVE
CVE-2026-64160
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-821, T1499
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=4058f742105ecfcbdf99e1139e6c1f74fb8e6db9 <2c8f4742bb76117d735f92a3932d85239b16c494
  2. Affected versionversion=4058f742105ecfcbdf99e1139e6c1f74fb8e6db9 <55970f238d495517edc961d55c44c772594d0969
  3. Affected versionversion=5.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4058f742105ecfcbdf99e1139e6c1f74fb8e6db9 <2c8f4742bb76117d735f92a3932d85239b16c494; version=4058f742105ecfcbdf99e1139e6c1f74fb8e6db9 <55970f238d495517edc961d55c44c772594d0969; version=5.18

Published CVSS scores

9.8Linux kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/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.

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-821Incorrect Synchronization
T1499Endpoint Denial of Service

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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