CVE-2026-89676Network attack vector

Kernel memory corruption via dangling COPY state ID

Published Sep 11, 2026 · Updated Sep 11, 2026

Use-after-free in the Linux kernel allows attackers to corrupt kernel memory during asynchronous NFSv4 COPY processing. nfsd4_copy() registers &u->copy->cp_stateid in s2s_cp_stateids before duplicating the COPY fields, leaving the IDR pointed at reused per-request COMPOUND-buffer memory instead of stable async_copy storage. Reachability requires an enabled NFS server and asynchronous COPY processing; later IDR walks can perform reference-count, IDR-removal, or free operations on invalid data.

CVSS severityUnavailable
Unscored
EPSS probability0.45%
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 the Linux kernel allows attackers to corrupt kernel memory during asynchronous NFSv4 COPY processing. nfsd4_copy() registers &u->copy->cp_stateid in s2s_cp_stateids before duplicating the COPY fields, leaving the IDR pointed at reused per-request COMPOUND-buffer memory instead of stable async_copy storage. Reachability requires an enabled NFS server and asynchronous COPY processing; later IDR walks can perform reference-count, IDR-removal, or free operations on invalid data.

The record

CVE
CVE-2026-89676
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1210
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=4.20
  2. Affected versionversion=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <14b978e8d05ce018d0afbeb6611833ef91713a02
  3. Affected versionversion=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <9b4e5e9ba5ae13808b8a6d229d87c54611ba0e7a
  4. Affected versionversion=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <d0beaee498e11880e72826026db0e9c9890fc114

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4.20; version=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <14b978e8d05ce018d0afbeb6611833ef91713a02; version=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <9b4e5e9ba5ae13808b8a6d229d87c54611ba0e7a; version=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <d0beaee498e11880e72826026db0e9c9890fc114

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1210Exploitation of Remote Services

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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