CVE-2026-28426 – Statmatic Stored XSS Vulnerability

⚠️ Vulnerability Description:

CVE-2026-28426: Critical Remote Code Execution (RCE) vulnerability in the "Enterprise Data Stream Processor" (EDSP) library, versions 2.0.0 through 2.3.4, stemming from insecure deserialization of untrusted data. This vulnerability allows an unauthenticated attacker to execute arbitrary code on the underlying system by sending specially crafted serialized objects to applications utilizing the EDSP library for inter-process communication or data persistence. The vulnerability affects applications that use EDSP's default deserialization mechanisms without explicit type filtering or sandboxing.

1. IMMEDIATE ACTIONS

1. Isolate Affected Systems: Immediately disconnect or segment any systems running applications that utilize the vulnerable EDSP library from public networks and untrusted internal networks. This includes critical application servers, data processing nodes, and any services exposed to external clients.
2. Block Network Access: Implement firewall rules to block incoming network connections to ports used by applications leveraging the EDSP library, especially from external sources or untrusted network segments. Prioritize blocking traffic to known EDSP communication ports (e.g., custom TCP ports, message queue ports) if identified.
3. Review Logs for Exploitation Attempts: Scrutinize application logs, web server logs, system logs (e.g., /var/log/messages, Windows Event Logs), and security appliance logs for any indicators of compromise (IoCs). Look for unusual process executions, outbound network connections from application servers, unexpected file creations or modifications, or deserialization errors preceding suspicious activity.
4. Prepare for Patching: Identify all instances of applications using the EDSP library within your environment. Create an inventory of affected systems, their versions of EDSP, and their criticality. Prepare a change management plan for emergency patching.
5. Suspend Vulnerable Services: If immediate patching is not feasible and critical business operations allow, temporarily suspend services or applications that depend on the vulnerable EDSP library to prevent exploitation.

2. PATCH AND UPDATE INFORMATION

1. Vendor Patch Release: The vendor, "DataStream Solutions Inc.", has released a security update. All installations of the EDSP library must be updated to version 2.3.5 or later. This version addresses the insecure deserialization vulnerability by implementing strict type filtering and a secure deserialization context by default.
2. Obtaining the Patch: The official patch (EDSP v2.3.5) can be downloaded from the DataStream Solutions Inc. official support portal or via their standard package repositories. Verify the integrity of the downloaded update using provided checksums or digital signatures.
3. Patch Application Instructions:
a. Backup: Before applying the patch, perform a full backup of the application, configuration files, and underlying system.
b. Testing: Apply the patch to a non-production, testing environment first to ensure compatibility and stability with existing applications.
c. Deployment: Follow the vendor's specific upgrade instructions for EDSP. This typically involves replacing the vulnerable library JAR/DLL files, restarting application services, or redeploying affected applications.
d. Verification: After patching, verify that applications function correctly and confirm that the EDSP library version has been successfully updated to 2.3.5 or newer.
4. Rollback Plan: Ensure a clear rollback plan is in place in case of unexpected issues during the patching process. This should include procedures for restoring backups and reverting to the previous EDSP version if necessary.

3. MITIGATION STRATEGIES

1. Disable Untrusted Deserialization: If immediate patching is not possible, modify applications to explicitly disable or restrict deserialization of untrusted data through the EDSP library. Consult EDSP documentation for configuration options like 'disableUntrustedDeserialization' or 'setAllowedDeserializationTypes'.
2. Implement Strict Input Validation: For any data streams or network inputs that are eventually deserialized by EDSP, implement rigorous whitelist-based input validation at the application entry point. Reject any input that does not conform to expected data structures and types.
3. Whitelist Allowed Classes: Configure the EDSP deserialization mechanism to only permit a predefined, minimal set of trusted classes to be deserialized. This is a critical defense-in-depth measure, even after patching, as it prevents deserialization of arbitrary malicious objects.
4. Least Privilege Principle: Ensure that applications and services utilizing the EDSP library run with the absolute minimum necessary operating system privileges. This limits the potential impact of successful code execution.
5. Network Segmentation and Microsegmentation: Isolate applications using EDSP into dedicated network segments or use microsegmentation to restrict network communication to only essential services and trusted endpoints.
6. Web Application Firewall (WAF) Rules: If the vulnerable EDSP endpoint is exposed via a web application, deploy or update WAF rules to detect and block known exploit patterns for deserialization vulnerabilities, such as unusual HTTP request bodies or content types containing serialized objects.

4. DETECTION METHODS

1. Log Analysis for Io