CVE-2026-89689Network attack vector

Remote kernel memory corruption via freed NFSv4 slot

Published Sep 11, 2026 · Updated Sep 11, 2026

Use-after-free in Linux 6.14 NFSD allows remote attackers to corrupt kernel heap memory through crafted NFSv4 SEQUENCE requests. nfsd4_sequence() can call free_session_slots() without checking that the current or concurrent high-numbered slot remains in use, then writes reply data through the freed slot pointer. The trigger requires an active NFSv4.1 session and a server-advertised slot reduction; successful exploitation corrupts kernel slab memory.

CVSS severityUnavailable
Unscored
EPSS probability0.60%
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 6.14 NFSD allows remote attackers to corrupt kernel heap memory through crafted NFSv4 SEQUENCE requests. nfsd4_sequence() can call free_session_slots() without checking that the current or concurrent high-numbered slot remains in use, then writes reply data through the freed slot pointer. The trigger requires an active NFSv4.1 session and a server-advertised slot reduction; successful exploitation corrupts kernel slab memory.

The record

CVE
CVE-2026-89689
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
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=6.14
  2. Affected versionversion=fc8738c68d0bbf5033dd98b4f63d277ecbd49fd7 <72d40b103bb03f0124d3a3c8f71a30cbafaf6afa
  3. Affected versionversion=fc8738c68d0bbf5033dd98b4f63d277ecbd49fd7 <b449b134e7762ddf98653a4b1d3e76d2d212ea64
  4. Affected versionversion=fc8738c68d0bbf5033dd98b4f63d277ecbd49fd7 <f5d22e372f4ac3eb287037a488c29691d52a6330

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.14; version=fc8738c68d0bbf5033dd98b4f63d277ecbd49fd7 <72d40b103bb03f0124d3a3c8f71a30cbafaf6afa; version=fc8738c68d0bbf5033dd98b4f63d277ecbd49fd7 <b449b134e7762ddf98653a4b1d3e76d2d212ea64; version=fc8738c68d0bbf5033dd98b4f63d277ecbd49fd7 <f5d22e372f4ac3eb287037a488c29691d52a6330

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)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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