Next.js RCE Incident Response — CVE-2025-55182

Type: Live Production Incident Response
Vulnerability: CVE-2025-55182 — React Server Components Insecure Deserialization (RCE)
Affected System: Next.js frontend + remote production server
Role: Cyber Security Intern — SenseLive Technologies
Date: February 24–26, 2026

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What Happened

A synchronized attack targeted both the frontend application and remote production server. The attack exploited CVE-2025-55182, a critical unauthenticated RCE vulnerability in the React Server Components (RSC) Flight protocol, leading to:

• Malicious script injection and unauthorized redirects on the frontend
• Unauthorized processes and filesystem modifications on the server
• Attempted credential harvesting post-exploitation

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My Response Actions

Frontend

• Audited the full build pipeline for compromised assets
• Removed malicious injections and redeployed from verified clean branch
• Patched Next.js to 15.x/16.x to mitigate CVE-2025-55182

Server

• Terminated unauthorized active sessions and background processes
• Rotated SSH administrative credentials
• Scanned persistence locations: /tmp, /var/www, cron jobs
• Checked for backdoors and web shells

Post-Incident

• Authored formal post-incident report submitted to CTO
• Recommended secret rotation for all environment variables, DB strings, and third-party API keys
• Initiated 24-hour high-alert monitoring window
• Proposed full Root Cause Analysis (RCA)

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CVE-2025-55182 — Technical Summary

Property	Detail
CVE ID	CVE-2025-55182
Component	React Server Components — RSC Flight Protocol
Attack Type	Insecure Deserialization → Unauthenticated RCE
Auth Required	None
Attack Complexity	Low — single crafted HTTP request
Default Config Vulnerable	Yes
Post-exploitation	Cloud credential harvesting, crypto mining
Affected Scope	~39% of cloud environments at time of discovery

Root cause: Attacker-controlled data influences server-side execution through the RSC payload deserialization logic. No developer code changes required to be vulnerable — standard create-next-app production builds are affected.

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Key Takeaways

1. Default framework configurations are not safe configurations
2. Script injection + server compromise arriving simultaneously suggests a coordinated, automated exploit campaign
3. Credential rotation must be treated as mandatory, not optional, post-compromise
4. Monitoring windows after remediation are as important as the remediation itself

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Responsible Disclosure Note

This report is published in sanitized form with authorization from SenseLive Technologies. Specific exploit payload details are withheld in line with responsible disclosure practices. All response actions were performed on systems owned by SenseLive Technologies during an active internship engagement.

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Skills Demonstrated

Incident Response CVE Analysis RCE Next.js Security React Server Components Script Injection SSH Hardening Credential Rotation Post-Incident Reporting Server Forensics Persistence Mechanism Detection Responsible Disclosure