CVE-2025-55182: 7 Critical Insights Into the React Server Components RCE

CVE-2025-55182 is a critical pre-authentication remote code execution (RCE) vulnerability in React Server Components (RSC), impacting production deployments of React 19 that rely on Server Actions and the Flight protocol. The vulnerability enables arbitrary code execution on the server without requiring authentication or user interaction, driven by a flaw in React’s deserialization pipeline when reconstructing server function references from client-supplied payloads.

This article provides an enterprise-grade, deeply technical breakdown of CVE-2025-55182: exploitation mechanics, deserialization attack surface, cloud-native risk paths, Kubernetes propagation models, server-side execution flows, WAF/EDR/SIEM detections, ATT&CK mapping, and actionable mitigations. It is designed for SOC leaders, SRE teams, cloud security architects, and product security engineers.

Table of Contents

• 1. Vulnerability Overview
• 2. React Server Components Internals
• 3. Detailed Exploitation Chain
• 4. Enterprise Attack Surface & Cloud Impact
• 5. Detection Engineering: SIEM, EDR, WAF, Syscalls
• 6. Mitigations, Patching, and Hardening
• 7. Visual Reference: Diagrams
• FAQ

1. Vulnerability Overview (CVE-2025-55182)

CVE-2025-55182 stems from unsafe deserialization of client-supplied Flight payloads inside the react-server-dom-* packages. The vulnerability allows attackers to construct a malicious payload that tricks the server into resolving an arbitrary “server reference”—a function pointer—to a controlled execution path.

React’s Flight protocol normally serializes “server actions” and “server references” as opaque identifiers. When the server rehydrates these references, it must verify their integrity. In vulnerable versions, the integrity check is insufficient, allowing an attacker to inject a new function reference—mapped to an internal module ID and export name—and invoke arbitrary JavaScript on the server.

2. Deep Dive: React Server Components Internals & Deserialization Flaws

The vulnerable component is the Flight Renderer, which reconstructs component trees and server references using structured JSON with special markers. Attackers abuse the following mechanisms:

• Module Map Resolution — React maps module IDs to server code bundles.
• Server Reference Tables — Symbol tables that store safe server actions.
• Deserializer / Rehydrator — Converts Flight protocol payloads into executable server functions.
• Call Dispatcher — Invokes functions by resolved reference ID.

In affected versions, the rehydrator accepts arbitrary attacker-provided module IDs and export names without enforcing origin constraints, leading to the ability to:

• Call require() on internal modules
• Access filesystem APIs via Node.js
• Execute arbitrary JS directly on the server
• Spawn child processes (child_process.exec)

3. Detailed Exploitation Chain

The exploit chain for CVE-2025-55182 consists of the following critical stages:

• Craft malicious Flight payload
  Attacker fabricates a JSON segment resembling a legitimate server reference but containing attacker-chosen module ID and export name.
• Server deserializes payload
  The vulnerable rehydrator trusts the incoming structure and loads the attacker’s module reference.
• Function pointer corruption
  Attacker replaces reference to a safe server action with a pointer to arbitrary code.
• Arbitrary execution
  The call dispatcher invokes the malicious reference, resulting in full RCE.

Example Malicious Payload (Simplified Flight Fragment)

{
  "$$typeof": "react.server.reference",
  "id": "file:///app/node_modules/fs/promises.js",
  "name": "writeFile",
  "bound": [
    "./shell.sh",
    "malicious content"
  ]
}

4. Enterprise Attack Surface & Cloud-Native Risk

Modern enterprise deployments using Next.js or custom RSC runtimes expand the blast radius significantly. Key risk domains include:

• Kubernetes — Attackers can pivot to sidecar containers, shared volumes, or cluster metadata endpoints.
• Service Mesh — RCE enables unauthorized service-to-service requests.
• Serverless (Vercel, AWS Lambda, Cloudflare) — Stateless functions become conduits for access to ephemeral storage and secrets.
• CI/CD systems — If RSC is used in build preview pipelines, attackers may execute code during build time.

Internal Reconnaissance Capabilities Post-RCE

• Enumerate /etc/passwd, environment variables, API keys
• Read application source code
• Extract JWT signing keys
• Query internal microservices via private network interfaces
• Access cloud metadata: 169.254.169.254

5. Detection Engineering: EDR, SIEM, WAF, Syscall Telemetry

Enterprise defenders should track the following detection domains:

5.1 Suspicious Node.js Behavior

process.openStdin() child_process.exec() require("fs").readFileSync() require("child_process").spawn()

5.2 WAF Signature Example

(?i)(react\.server\.reference|moduleId|serverReference|Flight)

5.3 SIEM Indicators (Flight Protocol)

Indicator	Description
Anomalous $typeof sequences	Unexpected server reference markers
Large or nested “bound” arrays	Payload mass-injection attempts
Module ID deviations	Non-whitelisted module paths being referenced
New server reference IDs	Unknown or attacker-generated function pointers

5.4 Syscall-Level Artifacts

• execve() from Node.js worker
• open() of unknown JS modules
• connect() to internal ASN ranges
• read() of /.config, /.cache, /var/task

6. Mitigations, Patching & Hardening

Patch immediately to the following fixed versions:

• React 19.0.1, 19.1.2, 19.2.1
• Next.js 15.0.5, 15.1.9, 16.0.7 and above

Hardening Guidance

• Isolate RSC runtime to non-privileged user
• Disable child_process where possible
• Restrict module resolution paths
• Add schema validation to inbound Flight payloads
• Enable runtime integrity checks for server reference tables

7. FALSE-POSITIVE-SAFE ModSecurity RULE

#############################################
# CVE-2025-55182 – React Server Components RCE
# False-Positive-Safe ModSecurity Rule Set
#############################################

# --- STEP 1: Identify React Server Components Context ---
SecRule REQUEST_METHOD "@streq POST" \
    "id:5518210,\
    phase:1,\
    pass,\
    nolog,\
    chain"
        SecRule REQUEST_URI "@rx (_rsc|__rsc|react-flight|server-action|_next/data)" \
            "setvar:tx.is_rsc=1"

# --- STEP 2: Detect React Server Reference Marker ---
SecRule TX:is_rsc "@eq 1" \
    "id:5518211,\
    phase:2,\
    pass,\
    t:none,t:urlDecodeUni,t:lowercase,\
    setvar:tx.react_score=+5,\
    msg:'RSC server reference marker detected',\
    tag:'cve-2025-55182',\
    chain"
        SecRule REQUEST_BODY "@rx \$\$typeof\s*[:=]\s*[\"']?react\.server\.reference"

# --- STEP 3: Detect Arbitrary Module / Export Resolution ---
SecRule TX:is_rsc "@eq 1" \
    "id:5518212,\
    phase:2,\
    pass,\
    t:none,t:urlDecodeUni,t:lowercase,\
    setvar:tx.react_score=+5,\
    msg:'Suspicious module resolution in RSC payload',\
    tag:'cve-2025-55182',\
    chain"
        SecRule REQUEST_BODY "@rx (moduleId|\"id\"|\"name\")\s*[:=]\s*[\"']?(file:|node:|\/|\.{2}\/)"

# --- STEP 4: Detect Node.js Runtime API Abuse ---
SecRule TX:is_rsc "@eq 1" \
    "id:5518213,\
    phase:2,\
    pass,\
    t:none,t:urlDecodeUni,t:lowercase,\
    setvar:tx.react_score=+5,\
    msg:'Node.js runtime API abuse in RSC payload',\
    tag:'cve-2025-55182',\
    chain"
        SecRule REQUEST_BODY "@rx (child_process|exec\s*\(|spawn\s*\(|require\s*\(\s*[\"']fs[\"']|process\.env)"

# --- STEP 5: Detect Abnormally Large Bound Arguments ---
SecRule TX:is_rsc "@eq 1" \
    "id:5518214,\
    phase:2,\
    pass,\
    setvar:tx.react_score=+3,\
    msg:'Large bound argument array in RSC payload',\
    tag:'cve-2025-55182',\
    chain"
        SecRule REQUEST_BODY "@rx \"bound\"\s*:\s*\[(?:[^\]]{300,})\]"

# --- STEP 6: FINAL BLOCK (Only if High Confidence) ---
SecRule TX:react_score "@ge 10" \
    "id:5518219,\
    phase:2,\
    block,\
    msg:'CVE-2025-55182: High-confidence React Server Components RCE attempt',\
    severity:CRITICAL,\
    tag:'cve-2025-55182',\
    tag:'react',\
    tag:'rce',\
    log"

WHY THIS RULE IS SAFE

✔ Blocks only when multiple exploit indicators appear
✔ Legit React Server Components traffic stays untouched
✔ Requires context + payload abuse + scoring threshold
✔ Production-safe for Next.js App Router
✔ Mirrors Akamai/Kona behavior-based logic

Scoring Summary

Indicator	Score
react.server.reference	+5
Arbitrary module resolution	+5
Node.js API keywords	+5
Large bound array	+3
Block Threshold	≥ 10

FAQ

For deeper context and related security research, you may also explore HackerVault’s guides on

• SQL Injection attacks and mitigation techniques
• Cross-Site Scripting (XSS) attack vectors
• Modern web application security best practices
• Writing effective WAF rules for modern attacks
• API security risks in modern applications
• Post-exploitation techniques used by attackers

For authoritative vulnerability details and official scoring, consult the

• Official NVD advisory for CVE-2025-55182
• OWASP guidance on insecure deserialization
• React Server Components security model