CVE-2025-39697

Data corruption and kernel crash via write-request race

Published Sep 5, 2025 · Updated Sep 5, 2025

A race condition in the Linux NFS client write path allows local users to corrupt NFS data, disclose stale memory, or crash the kernel. nfs_lock_and_join_requests() checks whether a request remains mapping-attached before taking the page-group lock, allowing nfs_inode_remove_request() to detach it concurrently. Exploitation requires write access on an existing NFS mount and overlapping buffered writes with forced writeback or invalidation; no other user interaction is required.

CVSS severity7.8
High
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 race condition in the Linux NFS client write path allows local users to corrupt NFS data, disclose stale memory, or crash the kernel. nfs_lock_and_join_requests() checks whether a request remains mapping-attached before taking the page-group lock, allowing nfs_inode_remove_request() to detach it concurrently. Exploitation requires write access on an existing NFS mount and overlapping buffered writes with forced writeback or invalidation; no other user interaction is required.

The record

CVE
CVE-2025-39697
Published
Sep 5, 2025
Updated
Sep 5, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-362, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 5, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 2025Record 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=4.14
  2. Affected versionversion=bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <202a3432d21ac060629a760fff3b0a39859da3ea
  3. Affected versionversion=bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <76d2e3890fb169168c73f2e4f8375c7cc24a765e
  4. Affected versionversion=bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <92278ae36935a54e65fef9f8ea8efe7e80481ace

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.14; version=bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <202a3432d21ac060629a760fff3b0a39859da3ea; version=bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <76d2e3890fb169168c73f2e4f8375c7cc24a765e; version=bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <92278ae36935a54e65fef9f8ea8efe7e80481ace

Published CVSS scores

4.7NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
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

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