CVE-2026-31404

System crash via premature NFSD export cleanup

Published Apr 3, 2026 · Updated Apr 3, 2026

Use-after-free in Linux Kernel NFSD allowed local users to crash the system through concurrent export-cache cleanup and reads. The svc_export_put() and expkey_put() paths released path and authentication-domain objects before an RCU grace period while readers still accessed them. Triggering the NULL dereference required NFSD to be running and root privileges to read the protected export-cache file; the CNA later rejected the record.

CVSS severity7.8
High
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Use-after-free in Linux Kernel NFSD allowed local users to crash the system through concurrent export-cache cleanup and reads. The svc_export_put() and expkey_put() paths released path and authentication-domain objects before an RCU grace period while readers still accessed them. Triggering the NULL dereference required NFSD to be running and root privileges to read the protected export-cache file; the CNA later rejected the record.

The record

CVE
CVE-2026-31404
Published
Apr 3, 2026
Updated
Apr 3, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 3, 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=6.14
  2. Affected versionversion=c224edca7af028828e2ad866b61d731b5e72b46d <2829e80d29b627886d12b5ea40856d56b516e67d
  3. Affected versionversion=c224edca7af028828e2ad866b61d731b5e72b46d <48db892356d6cb80f6942885545de4a6dd8d2a29
  4. Affected versionversion=c224edca7af028828e2ad866b61d731b5e72b46d <f5ab1bec5fa18731e0b1b1e60c9a68667ac73ea2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.14; version=c224edca7af028828e2ad866b61d731b5e72b46d <2829e80d29b627886d12b5ea40856d56b516e67d; version=c224edca7af028828e2ad866b61d731b5e72b46d <48db892356d6cb80f6942885545de4a6dd8d2a29; version=c224edca7af028828e2ad866b61d731b5e72b46d <f5ab1bec5fa18731e0b1b1e60c9a68667ac73ea2

Published CVSS scores

7.8kernel.orgCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
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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