CVE-2026-90039Hinoki check available

Kernel crash via premature NFSD state-table walk

Published Sep 16, 2026 · Updated Sep 16, 2026

NULL-pointer dereference in Linux 6.9 allows local users with CAP_SYS_ADMIN to crash the kernel through an NFSD unlock request. The procfs and netlink unlock handlers test nn->nfsd_serv, then walk nn->conf_id_hashtbl before nfsd_startup_net() allocates that table. Administrative capability and the listener-created startup window are required; successful triggering crashes the kernel without starting NFSD.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

NULL-pointer dereference in Linux 6.9 allows local users with CAP_SYS_ADMIN to crash the kernel through an NFSD unlock request. The procfs and netlink unlock handlers test nn->nfsd_serv, then walk nn->conf_id_hashtbl before nfsd_startup_net() allocates that table. Administrative capability and the listener-created startup window are required; successful triggering crashes the kernel without starting NFSD.

The record

CVE
CVE-2026-90039
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=1ac3629bf012592cb0320e52a1cceb319a05ad17 <0146467a2fce845cb6629979c3e9c58dd3d3a6a3
  2. Affected versionversion=1ac3629bf012592cb0320e52a1cceb319a05ad17 <104a51265042b4424085741c963cb858ac29ec0b
  3. Affected versionversion=1ac3629bf012592cb0320e52a1cceb319a05ad17 <2f3e6638aebc0ab8afb8b4e9816ea9a1cad85378
  4. Affected versionversion=6.9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=1ac3629bf012592cb0320e52a1cceb319a05ad17 <0146467a2fce845cb6629979c3e9c58dd3d3a6a3; version=1ac3629bf012592cb0320e52a1cceb319a05ad17 <104a51265042b4424085741c963cb858ac29ec0b; version=1ac3629bf012592cb0320e52a1cceb319a05ad17 <2f3e6638aebc0ab8afb8b4e9816ea9a1cad85378; version=6.9

Published CVSS scores

No CVSS assessment is available in this record.

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

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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