CVE-2026-12284: Software Security Vulnerability Vulnerability

LOW
Advisory Identifier: GHSA-q4vh-9cg5-4q62
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CVSS 3.7
CWE-346
Published
Advisory Summary

CVE-2026-12284 is a LOW (CVSS 3.7) security vulnerability vulnerability (CWE-346: Origin Validation Error) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not properly verify that the source of data or communication is valid.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-12284 at a Glance

CVE Identifier CVE-2026-12284
GHSA Identifier GHSA-q4vh-9cg5-4q62
Severity LOW
CVSS v3.1 Base Score 3.7
CWE Classification CWE-346: Origin Validation Error
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 3.7

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

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

How to Fix CVE-2026-12284

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-2026-12284, 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 CWE-346: Origin Validation Error, where the product does not properly verify that the source of data or communication is valid. 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

Mattermost Desktop App versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server (or a user with script access to a connected server view) to disconnect an active call belonging to a different connected server via the desktopAPI.leaveCall IPC message. Mattermost Advisory ID: MMSA-2026-00699

References

NVD — CVE-2026-12284 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-12284
Software Security Information SECURITY
https://mattermost.com/security-updates

Frequently Asked Questions

What is CVE-2026-12284?
CVE-2026-12284 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-346: Origin Validation Error.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-12284?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-12284?
CVE-2026-12284 has a CVSS v3.1 base score of 3.7 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-12284?
CVE-2026-12284 is classified under CWE-346: Origin Validation Error (The product does not properly verify that the source of data or communication is valid.).
How can I check Maven dependencies for CVE-2026-12284?
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-q4vh-9cg5-4q62",
  "modified" : "2026-09-17T18:31:46Z",
  "published" : "2026-09-17T18:31:46Z",
  "aliases" : [ "CVE-2026-12284" ],
  "details" : "Mattermost Desktop App versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server (or a user with script access to a connected server view) to disconnect an active call belonging to a different connected server via the desktopAPI.leaveCall IPC message. Mattermost Advisory ID: MMSA-2026-00699",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-12284"
  }, {
    "type" : "WEB",
    "url" : "https://mattermost.com/security-updates"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-346" ],
    "severity" : "LOW",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-17T16:17:21Z"
  }
}