HIGH CVSS 8.1
Published: 2026-04-03

CVE-2026-25773

mattermost focalboard Security Advisory (CVE-2026-25773)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-25773 impacting mattermost focalboard. Evaluated with CVSS Base Score of 8.1 (HIGH).

Original NVD Description

Source: NIST NVD
** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to sanitize category IDs before incorporating them into dynamic SQL statements when reordering categories. An attacker can inject a malicious SQL payload into the category id field, which is stored in the database and later executed unsanitized when the category reorder API processes the stored value. This Second-Order SQL Injection (Time-Based Blind) allows an authenticated attacker to exfiltrate sensitive data including password hashes of other users. NOTE: Focalboard as a standalone product is not maintained and no fix will be issued.

📊 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
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product mattermost / focalboard
Affected Versions 8.0.0
Weakness Enumeration CWE-89

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-2026-25773 impacting mattermost focalboard.

⚡ Nuclei Detection Template (YAML) cve-2026-25773.yaml
id: cve-2026-25773

info:
  name: mattermost focalboard - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-25773 affecting mattermost focalboard.
    Evaluation: ** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to sanitize category IDs before incorporating them into dynamic SQL statements when reord...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-25773
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
    cvss-score: 8.1
    cve-id: CVE-2026-25773
    cwe-id: CWE-89
  tags: cve,cve-2026-25773,mattermost,focalboard,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "focalboard"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-25773.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-25773
# Target: mattermost focalboard | CVSS: 8.1 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-25773 (mattermost focalboard)...")
    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 focalboard scope (8.0.0).")
        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)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-25773.sh
# Recommended Remediation & Patching Commands for CVE-2026-25773
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install focalboard 2>/dev/null || \
sudo dnf upgrade focalboard 2>/dev/null || \
sudo yum update focalboard

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

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

🛡️ 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.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

🔗 Verified Technical References

Authorities
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Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-25773 in mattermost focalboard?

Review vendor-specific security notices and update mattermost focalboard 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-2026-25773?

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-2026-25773?

CVE-2026-25773 is classified with a CVSS 3.1 Base Score of 8.1 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.1
HIGH SEVERITY
CVE ID CVE-2026-25773
Weakness CWE-89
Vendor mattermost
Product focalboard
Published 2026-04-03
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N