CVE-2025-71074

Kernel crash via FunctionFS open-removal race

Published Jan 13, 2026 · Updated Jan 13, 2026

Use-after-free in Linux Kernel FunctionFS before 6.19 allows local users to crash the kernel through concurrent endpoint open and removal. ffs_epfile_open() can increment ffs->opened after dynamic endpoint removal frees the object, leaving file->private_data dangling for later reads or writes. Reachability requires local access to a mounted FunctionFS endpoint and winning the open-removal race; published assessments report availability impact only.

CVSS severity4.7
Medium
EPSS probability0.11%
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 FunctionFS before 6.19 allows local users to crash the kernel through concurrent endpoint open and removal. ffs_epfile_open() can increment ffs->opened after dynamic endpoint removal frees the object, leaving file->private_data dangling for later reads or writes. Reachability requires local access to a mounted FunctionFS endpoint and winning the open-removal race; published assessments report availability impact only.

The record

CVE
CVE-2025-71074
Published
Jan 13, 2026
Updated
Jan 13, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-362
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 13, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b49c766856fb5901490de577e046149ebf15e39d
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e5bf5ee266633cb18fff6f98f0b7d59a62819eee

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b49c766856fb5901490de577e046149ebf15e39d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e5bf5ee266633cb18fff6f98f0b7d59a62819eee

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7NIST NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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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