CVE-2026-25614
📋 TL;DR
CVE-2026-25614 is a PHP object injection vulnerability in Blesta billing software that allows attackers to execute arbitrary code by deserializing untrusted data. This affects all Blesta installations running versions 3.x through 5.x before 5.13.3. Attackers can potentially gain full control of affected systems.
💻 Affected Systems
- Blesta
📦 What is this software?
Blesta by Phillipsdata
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and lateral movement within the network.
Likely Case
Unauthenticated attackers achieving remote code execution to install backdoors, steal sensitive billing data, or deploy ransomware.
If Mitigated
Limited impact if proper input validation and output encoding are implemented, though object injection could still lead to denial of service.
🎯 Exploit Status
Proof of concept code has been published in security advisories. The vulnerability requires minimal technical skill to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.13.3
Vendor Advisory: https://www.blesta.com/2026/01/28/security-advisory/
Restart Required: No
Instructions:
1. Backup your Blesta installation and database. 2. Download Blesta 5.13.3 or later from the official website. 3. Replace all files with the new version. 4. Verify the installation works correctly.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation to reject serialized objects in user-controlled data.
// PHP code to validate input
if (preg_match('/^[O]:\d+:"/', $user_input)) {
die('Invalid input detected');
}
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block serialized object patterns in HTTP requests.
- Restrict network access to Blesta administration interfaces using IP whitelisting or VPN requirements.
🔍 How to Verify
Check if Vulnerable:
Check Blesta version in admin panel at Settings > System > General. If version is between 3.0.0 and 5.13.2 inclusive, system is vulnerable.Check Version:
grep -r "define('BLESTA_VERSION'" /path/to/blesta/installation/Verify Fix Applied:
After patching, verify version shows 5.13.3 or higher in admin panel. Test serialized object input to ensure it's rejected.📡 Detection & Monitoring
Log Indicators:
- Unusual PHP deserialization errors in application logs
- Suspicious POST requests containing serialized object patterns (O:)
Network Indicators:
- HTTP requests with serialized PHP objects in parameters
- Unexpected outbound connections from Blesta server
SIEM Query:
source="blesta_logs" AND "unserialize" AND error