CVE-2026-89661: Software Security Vulnerability Vulnerability

UNKNOWN
Advisory Identifier: GHSA-5jhw-w88m-cjf3
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Advisory Summary

CVE-2026-89661 is a security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-89661 at a Glance

CVE Identifier CVE-2026-89661
GHSA Identifier GHSA-5jhw-w88m-cjf3
Severity N/A
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-89661

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-89661, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent post-shutdown use-after-free in unlock_filesystem Writing a filesystem path to /proc/fs/nfsd/unlock_filesystem runs nfsd4_cancel_copy_by_sb() before nfsd_mutex is held and before the handler confirms that nn->nfsd_serv is set. Once nfsd has shut down, nfs4_state_destroy_net() has freed nn->conf_id_hashtbl but left the pointer intact, so the cancel helper iterates freed slab memory as an array of struct list_head and then dereferences a bogus nfs4_client when it takes clp->async_lock. A local administrator holding CAP_SYS_ADMIN can reach this use-after-free by stopping the server and then writing to unlock_filesystem; KASAN reports a slab-use-after-free read in nfsd4_cancel_copy_by_sb(). nfsd4_revoke_states() walks the same state tables and for that reason already runs only under nfsd_mutex with nn->nfsd_serv confirmed present. Move the async COPY cancel into that protected section so every NFSv4 state-table walker on this path observes a running server. Async copies exist only while the server runs, so gating the cancel on nn->nfsd_serv loses nothing.

References

NVD — CVE-2026-89661 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89661
git.kernel.org/stable/c/0c1a755b72... WEB
https://git.kernel.org/stable/c/0c1a755b7212e0835398d4df5e782ea85ccd7476
git.kernel.org/stable/c/292d915d3b... WEB
https://git.kernel.org/stable/c/292d915d3ba6fd15eeb88351fa10581683073109

Frequently Asked Questions

What is CVE-2026-89661?
CVE-2026-89661 is a security vulnerability in Software classified as a security vulnerability vulnerability under General Security Weakness.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-89661?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-89661?
CVE-2026-89661 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89661?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5jhw-w88m-cjf3",
  "modified" : "2026-09-11T21:31:35Z",
  "published" : "2026-09-11T21:31:35Z",
  "aliases" : [ "CVE-2026-89661" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent post-shutdown use-after-free in unlock_filesystem\n\nWriting a filesystem path to /proc/fs/nfsd/unlock_filesystem runs\nnfsd4_cancel_copy_by_sb() before nfsd_mutex is held and before the\nhandler confirms that nn->nfsd_serv is set. Once nfsd has shut down,\nnfs4_state_destroy_net() has freed nn->conf_id_hashtbl but left the\npointer intact, so the cancel helper iterates freed slab memory as an\narray of struct list_head and then dereferences a bogus nfs4_client\nwhen it takes clp->async_lock. A local administrator holding\nCAP_SYS_ADMIN can reach this use-after-free by stopping the server and\nthen writing to unlock_filesystem; KASAN reports a slab-use-after-free\nread in nfsd4_cancel_copy_by_sb().\n\nnfsd4_revoke_states() walks the same state tables and for that reason\nalready runs only under nfsd_mutex with nn->nfsd_serv confirmed\npresent. Move the async COPY cancel into that protected section so\nevery NFSv4 state-table walker on this path observes a running server.\nAsync copies exist only while the server runs, so gating the cancel on\nnn->nfsd_serv loses nothing.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-89661"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/0c1a755b7212e0835398d4df5e782ea85ccd7476"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/292d915d3ba6fd15eeb88351fa10581683073109"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : null,
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-11T20:19:52Z"
  }
}