CVE-2026-25923
📋 TL;DR
This vulnerability in My Little Forum allows attackers to upload malicious files disguised as images, then trigger deserialization attacks that can delete arbitrary files on the server. It affects all My Little Forum installations prior to version 20260208.1. The attack requires the ability to upload images and post BBCode content.
💻 Affected Systems
- My Little Forum
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through arbitrary file deletion leading to data loss, service disruption, and potential privilege escalation.
Likely Case
Selective file deletion including configuration files, user data, or system files, causing service disruption and data loss.
If Mitigated
Limited impact if file uploads are restricted or input validation is enhanced, though the vulnerability remains present.
🎯 Exploit Status
Exploitation requires user account with image upload and BBCode posting permissions. The attack chain involves multiple steps: file upload, BBCode processing, and deserialization.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 20260208.1
Vendor Advisory: https://github.com/My-Little-Forum/mylittleforum/security/advisories/GHSA-wr9p-3c3g-78fw
Restart Required: No
Instructions:
1. Backup your forum database and files. 2. Download version 20260208.1 from GitHub releases. 3. Replace existing files with patched version. 4. Verify functionality.
🔧 Temporary Workarounds
Disable image uploads
allPrevent users from uploading images to block the initial attack vector.
Modify forum configuration to disable image uploads
Filter phar:// protocol
allAdd input validation to block phar:// protocol in URL processing.
Add protocol filtering in URL validation functions
🧯 If You Can't Patch
- Implement strict file upload restrictions allowing only verified image types
- Disable BBCode [img] tag processing or implement strict URL validation
🔍 How to Verify
Check if Vulnerable:
Check forum version in admin panel or source files. If version is earlier than 20260208.1, system is vulnerable.Check Version:
Check forum admin panel or examine source files for version informationVerify Fix Applied:
Verify version is 20260208.1 or later. Test image upload functionality with various file types.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads with non-image extensions
- Multiple failed upload attempts
- BBCode processing errors
Network Indicators:
- Large number of image upload requests
- Requests containing phar:// protocol strings
SIEM Query:
Search for 'phar://' in web server logs OR file upload events with non-standard image extensions