HIGH CVSS 7.7
Published: 2026-02-06

CVE-2025-13523

mattermost confluence Security Advisory (CVE-2025-13523)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-13523 impacting mattermost confluence. Evaluated with CVSS Base Score of 7.7 (HIGH).

Original NVD Description

Source: NIST NVD
Mattermost Confluence plugin version <1.7.0 fails to properly escape user-controlled display names in HTML template rendering which allows authenticated Confluence users with malicious display names to execute arbitrary JavaScript in victim browsers via sending a specially crafted OAuth2 connection link that, when visited, renders the attacker's display name without proper sanitization. Mattermost Advisory ID: MMSA-2025-00557

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
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
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product mattermost / confluence
Affected Versions *
Weakness Enumeration CWE-79

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-2025-13523 impacting mattermost confluence.

⚡ Nuclei Detection Template (YAML) cve-2025-13523.yaml
id: cve-2025-13523

info:
  name: mattermost confluence - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2025-13523 affecting mattermost confluence.
    Evaluation: Mattermost Confluence plugin version &lt;1.7.0 fails to properly escape user-controlled display names in HTML template rendering which allows authenti...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-13523
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N
    cvss-score: 7.7
    cve-id: CVE-2025-13523
    cwe-id: CWE-79
  tags: cve,cve-2025-13523,mattermost,confluence,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "confluence"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-13523.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-13523
# Target: mattermost confluence | CVSS: 7.7 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-13523 (mattermost confluence)...")
    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 confluence 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)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2025-13523.sh
# Recommended Remediation & Patching Commands for CVE-2025-13523
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install confluence 2>/dev/null || \
sudo dnf upgrade confluence 2>/dev/null || \
sudo yum update confluence

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

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

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2025-13523 in mattermost confluence?

Review vendor-specific security notices and update mattermost confluence 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-2025-13523?

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-2025-13523?

CVE-2025-13523 is classified with a CVSS 3.1 Base Score of 7.7 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.7
HIGH SEVERITY
CVE ID CVE-2025-13523
Weakness CWE-79
Vendor mattermost
Product confluence
Published 2026-02-06
Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N