CVE-2026-64389: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-fxvf-vm38-6pxw
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CVSS 8.2
Published
Advisory Summary

CVE-2026-64389 is a HIGH (CVSS 8.2) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-64389 at a Glance

CVE Identifier CVE-2026-64389
GHSA Identifier GHSA-fxvf-vm38-6pxw
Severity HIGH
CVSS v3.1 Base Score 8.2
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.2

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:N/I:L/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 None (C:N)
Integrity Low (I:L)
Availability High (A:H)

How to Fix CVE-2026-64389

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-2026-64389, 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: validate NTLMv2 response before updating session key ksmbd_auth_ntlmv2() derives the NTLMv2 session key into sess->sess_key before it verifies the NTLMv2 response. ksmbd_decode_ntlmssp_auth_blob() then continues into KEY_XCH even when ksmbd_auth_ntlmv2() failed. With SMB3 multichannel binding, the failed authentication operates on an existing session and the session setup error path does not expire binding sessions. A client can send a binding session setup with a bad NT proof and KEY_XCH and still modify sess->sess_key before STATUS_LOGON_FAILURE is returned. Relevant path: smb2_sess_setup() -> conn->binding = true -> ntlm_authenticate() -> session_user() -> ksmbd_decode_ntlmssp_auth_blob() -> ksmbd_auth_ntlmv2() -> calc_ntlmv2_hash() -> hmac_md5_usingrawkey(..., sess->sess_key) -> crypto_memneq() returns mismatch -> KEY_XCH arc4_crypt(..., sess->sess_key, ...) -> out_err without expiring the binding session Derive the base session key into a local buffer and copy it to sess->sess_key only after the proof matches. Return immediately on authentication failure so KEY_XCH is only processed after successful authentication.

References

NVD — CVE-2026-64389 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64389
git.kernel.org/stable/c/89ca7756d5... WEB
https://git.kernel.org/stable/c/89ca7756d5566ba636bb9092cdbe57dab095e136
git.kernel.org/stable/c/954d196beb... WEB
https://git.kernel.org/stable/c/954d196bebb2b50151cb96454c72dc113b2af1ac
git.kernel.org/stable/c/b56400364a... WEB
https://git.kernel.org/stable/c/b56400364aed5c34d6e1a0b493081290a5328a9c

Frequently Asked Questions

What is CVE-2026-64389?
CVE-2026-64389 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-2026-64389?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-64389?
CVE-2026-64389 has a CVSS v3.1 base score of 8.2 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H.
What CWE is associated with CVE-2026-64389?
CVE-2026-64389 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-64389?
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-fxvf-vm38-6pxw",
  "modified" : "2026-07-27T06:30:35Z",
  "published" : "2026-07-25T12:31:33Z",
  "aliases" : [ "CVE-2026-64389" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate NTLMv2 response before updating session key\n\nksmbd_auth_ntlmv2() derives the NTLMv2 session key into\nsess->sess_key before it verifies the NTLMv2 response.\nksmbd_decode_ntlmssp_auth_blob() then continues into KEY_XCH even\nwhen ksmbd_auth_ntlmv2() failed.\n\nWith SMB3 multichannel binding, the failed authentication operates on\nan existing session and the session setup error path does not expire\nbinding sessions. A client can send a binding session setup with a\nbad NT proof and KEY_XCH and still modify sess->sess_key before\nSTATUS_LOGON_FAILURE is returned.\n\nRelevant path:\n\n  smb2_sess_setup()\n    -> conn->binding = true\n    -> ntlm_authenticate()\n       -> session_user()\n       -> ksmbd_decode_ntlmssp_auth_blob()\n          -> ksmbd_auth_ntlmv2()\n             -> calc_ntlmv2_hash()\n             -> hmac_md5_usingrawkey(..., sess->sess_key)\n             -> crypto_memneq() returns mismatch\n          -> KEY_XCH arc4_crypt(..., sess->sess_key, ...)\n    -> out_err without expiring the binding session\n\nDerive the base session key into a local buffer and copy it to\nsess->sess_key only after the proof matches. Return immediately on\nauthentication failure so KEY_XCH is only processed after successful\nauthentication.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-64389"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/89ca7756d5566ba636bb9092cdbe57dab095e136"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/954d196bebb2b50151cb96454c72dc113b2af1ac"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b56400364aed5c34d6e1a0b493081290a5328a9c"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-25T10:17:22Z"
  }
}