CVE-2026-23957
📋 TL;DR
CVE-2026-23957 is a denial-of-service vulnerability in seroval library versions 1.4.0 and below. Attackers can craft malicious serialized data with manipulated array lengths to cause excessive CPU consumption during deserialization, potentially making applications unresponsive. This affects any application using vulnerable seroval versions for JavaScript value serialization/deserialization.
💻 Affected Systems
- seroval
📦 What is this software?
Seroval by Lxsmnsyc
⚠️ Risk & Real-World Impact
Worst Case
Complete application unavailability due to resource exhaustion, potentially affecting multiple services if seroval is used in shared infrastructure.
Likely Case
Degraded application performance and intermittent service disruptions when processing malicious payloads.
If Mitigated
Minimal impact with proper input validation and resource limits in place.
🎯 Exploit Status
Exploitation requires sending specially crafted serialized data to applications using seroval.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.4.1
Vendor Advisory: https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-66fc-rw6m-c2q6
Restart Required: Yes
Instructions:
1. Update seroval dependency to version 1.4.1 or higher. 2. Run npm update seroval or yarn upgrade seroval. 3. Restart the application. 4. Test serialization/deserialization functionality.
🔧 Temporary Workarounds
Input validation and size limits
allImplement strict input validation and size limits on serialized data before processing.
Resource limiting
allConfigure CPU and memory limits on processes using seroval to prevent complete resource exhaustion.
🧯 If You Can't Patch
- Implement strict input validation to reject serialized data with suspicious array length values.
- Deploy rate limiting and monitoring to detect and block DoS attempts.
🔍 How to Verify
Check if Vulnerable:
Check package.json or package-lock.json for seroval version <=1.4.0.Check Version:
npm list seroval or yarn list serovalVerify Fix Applied:
Verify seroval version is 1.4.1 or higher in package.json and test deserialization with various inputs.📡 Detection & Monitoring
Log Indicators:
- Unusually high CPU usage by processes using seroval
- Increased deserialization processing times
- Application timeouts or crashes during data processing
Network Indicators:
- Large serialized payloads being sent to applications
- Repeated serialized data requests to endpoints using seroval
SIEM Query:
process.cpu_usage > 90% AND process.name contains 'node' AND process.args contains 'seroval'