CRITICAL CVSS 9.1
Published: 2026-02-09

CVE-2026-25923

mylittleforum my_little_forum Security Advisory (CVE-2026-25923)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-25923 impacting mylittleforum my_little_forum. Evaluated with CVSS Base Score of 9.1 (CRITICAL).

Original NVD Description

Source: NIST NVD
my little forum is a PHP and MySQL based internet forum that displays the messages in classical threaded view. Prior to 20260208.1, the application fails to filter the phar:// protocol in URL validation, allowing attackers to upload a malicious Phar Polyglot file (disguised as JPEG) via the image upload feature, trigger Phar deserialization through BBCode [img] tag processing, and exploit Smarty 4.1.0 POP chain to achieve arbitrary file deletion. This vulnerability is fixed in 20260208.1.

📊 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
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product mylittleforum / my_little_forum
Affected Versions *
Weakness Enumeration CWE-434

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-2026-25923 impacting mylittleforum my_little_forum.

⚡ Nuclei Detection Template (YAML) cve-2026-25923.yaml
id: cve-2026-25923

info:
  name: mylittleforum my_little_forum - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2026-25923 affecting mylittleforum my_little_forum.
    Evaluation: my little forum is a PHP and MySQL based internet forum that displays the messages in classical threaded view. Prior to 20260208.1, the application fa...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-25923
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
    cvss-score: 9.1
    cve-id: CVE-2026-25923
    cwe-id: CWE-434
  tags: cve,cve-2026-25923,mylittleforum,my_little_forum,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "my_little_forum"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-25923.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-25923
# Target: mylittleforum my_little_forum | CVSS: 9.1 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-25923 (mylittleforum my_little_forum)...")
    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 mylittleforum my_little_forum 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-2026-25923.sh
# Recommended Remediation & Patching Commands for CVE-2026-25923
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install my_little_forum 2>/dev/null || \
sudo dnf upgrade my_little_forum 2>/dev/null || \
sudo yum update my_little_forum

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

# 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-2026-25923 in mylittleforum my_little_forum?

Review vendor-specific security notices and update mylittleforum my_little_forum 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-2026-25923?

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-2026-25923?

CVE-2026-25923 is classified with a CVSS 3.1 Base Score of 9.1 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
9.1
CRITICAL SEVERITY
CVE ID CVE-2026-25923
Weakness CWE-434
Vendor mylittleforum
Product my_little_forum
Published 2026-02-09
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H