CVE-2026-2964: Higuma Webaudiorecorder.js RCE Vulnerability

CVE-2026-2964 Overview

A prototype pollution vulnerability was identified in higuma web-audio-recorder-js versions 0.1 and 0.1.1. The vulnerability exists in the extend function within the library file lib/WebAudioRecorder.js, specifically in the Dynamic Config Handling component. This flaw allows for improperly controlled modification of object prototype attributes (CWE-94: Code Injection), which could enable attackers to manipulate the behavior of JavaScript objects throughout the application.

Critical Impact

Prototype pollution vulnerabilities can lead to property injection attacks, potentially enabling denial of service, security bypass, or in some cases remote code execution depending on how the polluted properties are used by the application.

Affected Products

• higuma webaudiorecorder.js 0.1
• higuma webaudiorecorder.js 0.1.1

Discovery Timeline

• February 23, 2026 - CVE CVE-2026-2964 published to NVD
• February 26, 2026 - Last updated in NVD database

Technical Details for CVE-2026-2964

Vulnerability Analysis

The vulnerability resides in the extend function of the lib/WebAudioRecorder.js library, which is responsible for Dynamic Config Handling. This function fails to properly validate or sanitize input properties before merging them into JavaScript objects. When user-controlled input is passed to this function, an attacker can inject properties like __proto__, constructor, or prototype that modify the base Object prototype.

Prototype pollution occurs when an attacker can modify the prototype of a base object, causing all objects that inherit from that prototype to be affected. In JavaScript applications, this can have cascading effects throughout the application logic, potentially leading to security bypasses, application crashes, or exploitation of downstream code that relies on predictable object properties.

The vendor was contacted early about this disclosure but did not respond in any way, leaving users without an official patch.

Root Cause

The root cause of this vulnerability is insufficient input validation in the extend function when processing dynamic configuration objects. The function does not implement proper safeguards to prevent special prototype-related properties from being set, allowing attackers to inject malicious properties that pollute the Object prototype chain.

Attack Vector

The attack can be launched remotely via network access. An attacker would need to provide a specially crafted configuration object containing prototype pollution payloads such as __proto__ or constructor.prototype properties. When the vulnerable extend function processes this malicious input, the injected properties are merged into the prototype chain.

While the attack is network-accessible, it is noted that attacks of this nature are highly complex and the exploitability is considered difficult, requiring the attacker to have low-level privileges and understanding of how the polluted properties would be used by the application. The exploit is publicly available and might be used.

For technical details on the exploitation mechanism, refer to the VulDB CTI ID #347331 and VulDB #347331 advisories.

Detection Methods for CVE-2026-2964

Indicators of Compromise

• Unexpected properties appearing on base JavaScript objects that were not explicitly defined
• Application behavior anomalies related to object property access returning unexpected values
• Web application firewall logs showing payloads containing __proto__, constructor, or prototype strings in request parameters

Detection Strategies

• Implement JavaScript runtime monitoring to detect modifications to Object.prototype
• Deploy web application firewall rules to filter requests containing prototype pollution payloads (__proto__, constructor.prototype)
• Use static analysis tools to identify usage of vulnerable versions of web-audio-recorder-js (versions 0.1 and 0.1.1)
• Conduct dependency audits using npm audit or similar tools to flag vulnerable packages

Monitoring Recommendations

• Monitor application logs for unusual object property access patterns or type errors
• Implement integrity checking for critical JavaScript object prototypes at runtime
• Set up alerts for dependency vulnerability notifications related to higuma/web-audio-recorder-js

How to Mitigate CVE-2026-2964

Immediate Actions Required

• Audit your codebase to identify usage of higuma/web-audio-recorder-js versions 0.1 or 0.1.1
• Consider replacing the vulnerable library with an actively maintained alternative
• Implement input validation to sanitize configuration objects before passing them to the extend function
• Use Object.freeze(Object.prototype) as a defense-in-depth measure where application compatibility allows

Patch Information

No official patch is currently available from the vendor. The vendor was contacted early about this disclosure but did not respond in any way. Users should consider alternative mitigation strategies or library replacement.

For more information, see the VulDB Submission #755221.

Workarounds

• Implement a wrapper function around the vulnerable extend function that filters out dangerous properties (__proto__, constructor, prototype)
• Use Object.create(null) for configuration objects to create prototype-less objects that are immune to prototype pollution
• Consider using the Map data structure instead of plain objects for dynamic configuration handling
• Deploy content security policies and input sanitization at the application boundary

# Check for vulnerable package versions in your project
npm ls web-audio-recorder-js

# Alternative: Use npm audit to scan for known vulnerabilities
npm audit

# Consider creating a prototype-safe extend function in your application
# that explicitly filters dangerous properties before merging objects