CVE-2026-23956
📋 TL;DR
seroval library versions 1.4.0 and below contain vulnerabilities in RegExp serialization that can cause memory exhaustion or ReDoS (Regular Expression Denial of Service) during deserialization. Attackers can exploit these by providing specially crafted patterns that either consume excessive memory or trigger catastrophic backtracking. This affects any application using vulnerable seroval versions for JavaScript value serialization.
💻 Affected Systems
- seroval
📦 What is this software?
Seroval by Lxsmnsyc
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service through memory exhaustion or CPU exhaustion via ReDoS, potentially crashing the JavaScript runtime and making the application unavailable.
Likely Case
Application performance degradation or temporary unavailability due to resource exhaustion attacks, particularly affecting endpoints that process user-controlled serialized data.
If Mitigated
Minimal impact with proper input validation, rate limiting, and updated library versions preventing exploitation.
🎯 Exploit Status
Exploitation requires the ability to provide serialized data to the application, which could be through various input vectors.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.4.1
Vendor Advisory: https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-hx9m-jf43-8ffr
Restart Required: No
Instructions:
1. Update seroval dependency to version 1.4.1 or higher. 2. For npm: run 'npm update seroval'. 3. For yarn: run 'yarn upgrade seroval'. 4. Verify the update in package.json.
🔧 Temporary Workarounds
Input validation for serialized data
allImplement strict validation and sanitization of user-provided serialized data before deserialization.
Rate limiting deserialization endpoints
allApply rate limiting to endpoints that accept serialized data to mitigate DoS impact.
🧯 If You Can't Patch
- Implement strict input validation to reject serialized data containing RegExp patterns from untrusted sources.
- Deploy Web Application Firewall (WAF) rules to detect and block patterns indicative of ReDoS or memory exhaustion attacks.
🔍 How to Verify
Check if Vulnerable:
Check package.json or lock files for seroval version ≤1.4.0. For npm: 'npm list seroval'. For yarn: 'yarn list seroval'.Check Version:
npm list seroval | grep serovalVerify Fix Applied:
Confirm seroval version is ≥1.4.1 using version check command and test deserialization with known safe patterns.📡 Detection & Monitoring
Log Indicators:
- Unusually high memory usage spikes
- Extended processing times for deserialization operations
- Application crashes or restarts
Network Indicators:
- Increased request volume to serialization/deserialization endpoints
- Patterns of requests with large payloads
SIEM Query:
source="application_logs" AND (message="*memory*" OR message="*deserialization*") AND severity="ERROR"