HIGH CVSS 7.6
Published: 2026-02-16

CVE-2026-1046

mattermost mattermost_desktop Security Advisory (CVE-2026-1046)
โ†— Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-1046 impacting mattermost mattermost_desktop. Evaluated with CVSS Base Score of 7.6 (HIGH).

Original NVD Description

Source: NIST NVD
Mattermost Desktop App versions <=6.0 6.2.0 5.2.13.0 fail to validate help links which allows a malicious Mattermost server to execute arbitrary executables on a userโ€™s system via the user clicking on certain items in the Help menu Mattermost Advisory ID: MMSA-2026-00577

๐Ÿ“Š CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
Low (PR:L)
Standard user access required
User Interaction
Required (UI:R)
User must click or open resource
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
High (C:H)
Total information disclosure
Integrity
None (I:N)
No system modification impact
Availability
Low (A:L)
Partial service performance degradation

๐ŸŽฏ Affected Versions Matrix

Affected Product mattermost / mattermost_desktop
Affected Versions *
Weakness Enumeration CWE-939

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-1046 impacting mattermost mattermost_desktop.

โšก Nuclei Detection Template (YAML) cve-2026-1046.yaml
id: cve-2026-1046

info:
  name: mattermost mattermost_desktop - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-1046 affecting mattermost mattermost_desktop.
    Evaluation: Mattermost Desktop App versions &lt;=6.0 6.2.0 5.2.13.0 fail to validate help links which allows a malicious Mattermost server to execute arbitrary ex...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-1046
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:L
    cvss-score: 7.6
    cve-id: CVE-2026-1046
    cwe-id: CWE-939
  tags: cve,cve-2026-1046,mattermost,mattermost_desktop,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "mattermost_desktop"
        part: body
๐Ÿ PoC Exploit & Verification Probe (Python 3) poc_cve-2026-1046.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-1046
# Target: mattermost mattermost_desktop | CVSS: 7.6 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-1046 (mattermost mattermost_desktop)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against mattermost mattermost_desktop scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
๐Ÿ›ก๏ธ Quick Patch & Remediation Script (Bash) patch_cve-2026-1046.sh
# Recommended Remediation & Patching Commands for CVE-2026-1046
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install mattermost_desktop 2>/dev/null || \
sudo dnf upgrade mattermost_desktop 2>/dev/null || \
sudo yum update mattermost_desktop

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i mattermost_desktop 2>/dev/null || rpm -qa | grep -i mattermost_desktop

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

๐Ÿ›ก๏ธ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
โš ๏ธ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

๐Ÿ”— Verified Technical References

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

โ“ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-1046 in mattermost mattermost_desktop?

Review vendor-specific security notices and update mattermost mattermost_desktop packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-1046?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-1046?

CVE-2026-1046 is classified with a CVSS 3.1 Base Score of 7.6 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.6
HIGH SEVERITY
CVE ID CVE-2026-1046
Weakness CWE-939
Vendor mattermost
Product mattermost_desktop
Published 2026-02-16
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:L