CVE-2026-89673Network attack vectorHinoki check available

Kernel memory disclosure via miscalculated XDR padding

Published Sep 11, 2026 · Updated Sep 11, 2026

Information disclosure in Linux nfsd allows remote attackers to read stale reply-page data through flexfiles GETDEVICEINFO replies. The nfsd4_ff_encode_getdeviceinfo function reserves 16 plus the unaligned string lengths, although xdr_encode_opaque writes two 4-byte length fields and rounds each string to a 4-byte boundary. Access to an NFSv4.1 flexfiles server is required, and each affected reply exposes 2–8 bytes while misaligning the following version-list decode.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Information disclosure in Linux nfsd allows remote attackers to read stale reply-page data through flexfiles GETDEVICEINFO replies. The nfsd4_ff_encode_getdeviceinfo function reserves 16 plus the unaligned string lengths, although xdr_encode_opaque writes two 4-byte length fields and rounds each string to a 4-byte boundary. Access to an NFSv4.1 flexfiles server is required, and each affected reply exposes 2–8 bytes while misaligning the following version-list decode.

The record

CVE
CVE-2026-89673
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1005
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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=6.4.16 <6.12.109
  2. Affected versionversion=6.4.16 <6.18.50
  3. Affected versionversion=6.4.16 <7.2.4
  4. Affected versionversion=6.4.16 <7.3-rc1
  5. Affected versionversion=efcae97fa425ca6db9d126e37daccf2d7225cb09 <41ebca28e17f84293650598f86bd69532ec1a8e0
  6. Affected versionversion=efcae97fa425ca6db9d126e37daccf2d7225cb09 <62e5949f0dd5ec837af144860ff908369df4c7c9
  7. Affected versionversion=efcae97fa425ca6db9d126e37daccf2d7225cb09 <74015b7be806ad9e21d46f7bd2831df280c6c783
  8. Affected versionversion=efcae97fa425ca6db9d126e37daccf2d7225cb09 <8b989aaec85e1293a871d602590c951fe44b8647

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.4.16 <6.12.109; version=6.4.16 <6.18.50; version=6.4.16 <7.2.4; version=6.4.16 <7.3-rc1; version=efcae97fa425ca6db9d126e37daccf2d7225cb09 <41ebca28e17f84293650598f86bd69532ec1a8e0; version=efcae97fa425ca6db9d126e37daccf2d7225cb09 <62e5949f0dd5ec837af144860ff908369df4c7c9; version=efcae97fa425ca6db9d126e37daccf2d7225cb09 <74015b7be806ad9e21d46f7bd2831df280c6c783; version=efcae97fa425ca6db9d126e37daccf2d7225cb09 <8b989aaec85e1293a871d602590c951fe44b8647

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

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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)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1005Data from Local System

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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