CVE-2026-89788: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-29wc-2986-775f
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CVSS 9.8
Published
Advisory Summary

CVE-2026-89788 is a CRITICAL (CVSS 9.8) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-89788 at a Glance

CVE Identifier CVE-2026-89788
GHSA Identifier GHSA-29wc-2986-775f
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-89788

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-2026-89788, 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: ksmbd: fix tree connection use-after-free in smb2_tree_connect() ksmbd_tree_conn_connect() publishes a new tree connection in sess->tree_conns with a single reference and returns its pointer to smb2_tree_connect(). The handler continues to initialize the object and build the response after publication. A concurrent session logoff can erase the connection and drop that reference, freeing the object while the handler still uses it. BUG: KASAN: slab-use-after-free in smb2_tree_connect+0xe3d/0xf90 smb2_tree_connect (fs/smb/server/smb2pdu.c:2872) handle_ksmbd_work process_one_work worker_thread kthread After xa_store() succeeds, take a second reference before releasing tree_conns_lock. The original reference belongs to the xarray entry and the second belongs to the creating smb2_tree_connect() handler. Keep the references balanced in every path: - On normal exit or an error after publication, smb2_tree_connect() drops its creator reference. Error cleanup also calls ksmbd_tree_conn_disconnect(), which drops the xarray reference only if it removes the exact entry. - SMB2 TREE_DISCONNECT uses the same helper to remove the entry and drop its xarray reference. The request's existing lookup reference remains owned by the request and is released by the existing cleanup. - Session LOGOFF removes each entry and drops its xarray reference. If it wins the race, later cleanup sees that the entry is gone and does not drop that reference again. To enforce this ownership, claim the disconnected state and erase the exact entry atomically under tree_conns_lock. This guarantees one drop for the xarray reference and one drop by each in-flight user, regardless of which teardown path wins. If logoff removes the entry before initialization completes, fail the connect instead of marking the detached object TREE_CONNECTED.

References

NVD — CVE-2026-89788 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89788
git.kernel.org/stable/c/4e30fbd26e... WEB
https://git.kernel.org/stable/c/4e30fbd26e84efa2e5cbec4eb11e126ac0c79313
git.kernel.org/stable/c/b5ec6c462a... WEB
https://git.kernel.org/stable/c/b5ec6c462aab1062cf5d1e667ba7c6442f737055

Frequently Asked Questions

What is CVE-2026-89788?
CVE-2026-89788 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-2026-89788?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-89788?
CVE-2026-89788 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-89788?
CVE-2026-89788 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89788?
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-29wc-2986-775f",
  "modified" : "2026-09-16T15:30:57Z",
  "published" : "2026-09-16T09:30:30Z",
  "aliases" : [ "CVE-2026-89788" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix tree connection use-after-free in smb2_tree_connect()\n\nksmbd_tree_conn_connect() publishes a new tree connection in\nsess->tree_conns with a single reference and returns its pointer to\nsmb2_tree_connect(). The handler continues to initialize the object and\nbuild the response after publication. A concurrent session logoff can\nerase the connection and drop that reference, freeing the object while\nthe handler still uses it.\n\nBUG: KASAN: slab-use-after-free in smb2_tree_connect+0xe3d/0xf90\n  smb2_tree_connect (fs/smb/server/smb2pdu.c:2872)\n  handle_ksmbd_work\n  process_one_work\n  worker_thread\n  kthread\n\nAfter xa_store() succeeds, take a second reference before releasing\ntree_conns_lock. The original reference belongs to the xarray entry and\nthe second belongs to the creating smb2_tree_connect() handler.\n\nKeep the references balanced in every path:\n\n- On normal exit or an error after publication, smb2_tree_connect()\n  drops its creator reference. Error cleanup also calls\n  ksmbd_tree_conn_disconnect(), which drops the xarray reference only if\n  it removes the exact entry.\n- SMB2 TREE_DISCONNECT uses the same helper to remove the entry and drop\n  its xarray reference. The request's existing lookup reference remains\n  owned by the request and is released by the existing cleanup.\n- Session LOGOFF removes each entry and drops its xarray reference. If\n  it wins the race, later cleanup sees that the entry is gone and does\n  not drop that reference again.\n\nTo enforce this ownership, claim the disconnected state and erase the\nexact entry atomically under tree_conns_lock. This guarantees one drop\nfor the xarray reference and one drop by each in-flight user, regardless\nof which teardown path wins. If logoff removes the entry before\ninitialization completes, fail the connect instead of marking the\ndetached object TREE_CONNECTED.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-89788"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/4e30fbd26e84efa2e5cbec4eb11e126ac0c79313"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b5ec6c462aab1062cf5d1e667ba7c6442f737055"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-16T09:17:09Z"
  }
}