CVE-2026-112309 in set-get
Summary
by MITRE • 10/19/2026
@rvf/set-get before 7.0.4 contains a prototype pollution vulnerability in setPath that allows unauthenticated attackers to overwrite properties of shared built-in functions via inherited Object.prototype methods. Attackers can submit a form field named hasOwnProperty.call through @rvf/core form parsing to replace the shared function property, causing process-wide denial of service until restart.
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Analysis
by VulDB Data Team • 10/19/2026
The vulnerability identified in versions of the @rvf/set-get library prior to 7.0.4 constitutes a critical prototype pollution flaw within the setPath utility function. This security issue stems from an insufficient validation mechanism when processing nested object properties, allowing unauthenticated attackers to manipulate the JavaScript Object.prototype chain. By exploiting this weakness, malicious actors can inject or overwrite standard built-in methods such as hasOwnProperty, thereby corrupting the shared state of the runtime environment rather than just a specific application instance.
The technical root cause lies in how the library handles property assignment paths without adequately checking for existing prototype properties before setting them on the target object. When an attacker submits a form field with the name hasOwnProperty.call through @rvf/core, the parsing logic interprets this as a path to traverse and set a value. Instead of restricting operations to own enumerable properties or validating against reserved names, the code inadvertently writes directly onto the Object prototype. This action effectively replaces the native implementation of critical object methods across all objects in the current execution context.
The operational impact of this vulnerability is severe, leading primarily to process-wide denial of service conditions. Because JavaScript engines rely heavily on standard built-in functions for basic operations such as property enumeration and existence checks, overwriting these methods disrupts fundamental language behaviors. Applications utilizing affected versions may experience erratic behavior, crashes, or complete unresponsiveness until the server process is restarted. This disruption affects all users interacting with the application during the window of exploitation, as the corruption persists in memory for the lifetime of the Node.js event loop.
From a classification perspective, this vulnerability aligns with CWE-1325, which covers Incorrectly Controlled Modification of Object Prototype Attributes, and maps to MITRE ATT&CK technique T1078, specifically relating to valid accounts or system-level manipulation that undermines integrity. The attack vector is particularly dangerous because it can be triggered via standard HTTP form submissions without requiring authentication, making it accessible to any external actor with network connectivity to the vulnerable service endpoint.
Mitigation strategies must prioritize immediate upgrading of the @rvf/set-get dependency to version 7.0.4 or later, where this prototype pollution path has been patched through stricter input validation and safe object manipulation practices. In environments where an upgrade is not immediately feasible, defensive coding patterns such as using Object.create(null) for data structures that do not require prototype inheritance can isolate the application from prototype-based attacks. Additionally implementing strict allowlists for form field names or sanitizing inputs to prevent traversal of reserved property paths provides a necessary layer of defense against similar injection techniques in related libraries.