CVE-2026-64258

Local service interruption via stale FUSE queue entry

Published Jul 25, 2026 · Updated Jul 25, 2026

A NULL-pointer dereference in Linux Kernel 6.16 allows local users to interrupt host service through the FUSE io_uring path. When a userspace-ring copy fails, fuse_uring_req_end() clears ent->fuse_req but leaves the FRRS_FUSE_REQ entry on ent_w_req_queue, allowing expiration scanning to dereference NULL before queue removal. Triggerability requires the FUSE io_uring request path, a failed copy, and expiration scanning during that queue window; the exact interruption mode is not published.

CVSS severity5.5
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A NULL-pointer dereference in Linux Kernel 6.16 allows local users to interrupt host service through the FUSE io_uring path. When a userspace-ring copy fails, fuse_uring_req_end() clears ent->fuse_req but leaves the FRRS_FUSE_REQ entry on ent_w_req_queue, allowing expiration scanning to dereference NULL before queue removal. Triggerability requires the FUSE io_uring request path, a failed copy, and expiration scanning during that queue window; the exact interruption mode is not published.

The record

CVE
CVE-2026-64258
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 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=4fea593e625cd50d4d11be227007849b12f17bfb <0a7f33010c0e4cd92937e088a54350381fd0fbf2
  2. Affected versionversion=4fea593e625cd50d4d11be227007849b12f17bfb <0b466cf1b96e191b06b496c4de79da15315c3a9a
  3. Affected versionversion=4fea593e625cd50d4d11be227007849b12f17bfb <1c57a69be962d459c5e705f5cb4355b841b3461c
  4. Affected versionversion=6.16

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4fea593e625cd50d4d11be227007849b12f17bfb <0a7f33010c0e4cd92937e088a54350381fd0fbf2; version=4fea593e625cd50d4d11be227007849b12f17bfb <0b466cf1b96e191b06b496c4de79da15315c3a9a; version=4fea593e625cd50d4d11be227007849b12f17bfb <1c57a69be962d459c5e705f5cb4355b841b3461c; version=6.16

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/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-476NULL Pointer Dereference
T1499.004Endpoint Denial of Service: Application 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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