CVE-2026-120438
Received Received - Intake

Integer Overflow in QuickJS-NG Leading to Heap Buffer Overflow

Publication date: 2026-11-02

Last updated on: 2026-11-02

Assigner: VulnCheck

Description
QuickJS-NG before 0.16.0 contains an integer overflow in js_proxy_get_own_property_names() in quickjs.c that causes a heap buffer overflow on 32-bit hosts. Attackers running JavaScript can return a large array-like object from a Proxy ownKeys trap to wrap the allocation size, causing crashes or potential code execution.

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Meta Information

Published
2026-11-02
Last Modified
2026-11-02
Generated
2026-11-02
AI Q&A
2026-11-02
EPSS Evaluated
N/A
NVD
CVE-2026-120438

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
quickjs-ng QuickJS-NG 0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-190 The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

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Executive Summary

CVE-2026-120438 is a heap buffer overflow vulnerability in QuickJS-NG versions before 0.16.0. It occurs in the js_proxy_get_own_property_names() function due to an integer overflow during Proxy ownKeys enumeration on 32-bit systems. Attackers can exploit this by returning a large array-like object from a Proxy ownKeys trap, causing crashes or potential code execution.

Detection Guidance

Detecting this vulnerability requires checking the QuickJS-NG version in use. Run 'quickjs --version' or inspect the library version in your application dependencies. If the version is below 0.16.0, the system is vulnerable. Additionally, monitor for crashes during JavaScript execution, especially when using Proxy objects with ownKeys traps.

Impact Analysis

This vulnerability can cause crashes or arbitrary code execution on 32-bit systems running vulnerable QuickJS-NG versions. It may affect applications using JavaScript Proxies with ownKeys traps, particularly in embedded systems, IoT devices, or WASM runtimes. Systems running on 64-bit platforms are not affected.

Compliance Impact

This vulnerability primarily affects systems running QuickJS-NG on 32-bit platforms, potentially leading to crashes or arbitrary code execution. While it does not directly impact GDPR or HIPAA compliance, it could indirectly affect compliance by enabling unauthorized code execution or data access if exploited. Organizations handling sensitive data under these regulations should ensure affected versions are patched to mitigate potential risks.

Mitigation Strategies

Upgrade QuickJS-NG to version 0.16.0 or later immediately. If upgrading is not possible, restrict execution of untrusted JavaScript code or disable Proxy functionality in environments where 32-bit systems are used. Apply patches from the official release if available.

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