CVE-2026-44966 is a prototype pollution vulnerability in shepherdwind's velocity.js (<= 2.1.5). The issue arises during the handling of #set directives in Velocity templates, enabling an attacker who can control template content to modify JavaScript's Object.prototype. This can cause serious impacts such as Denial of Service or Remote Code Execution depending on the server environment. The vulnerability has a CVSS 3.1 score of 8.3 (high severity) with network attack vector, low attack complexity, no privileges or user interaction required, and impacts on confidentiality, integrity, and availability. No patch or official remediation level is currently documented.

An attacker able to supply malicious Velocity templates can exploit this vulnerability to perform prototype pollution, potentially causing Denial of Service or Remote Code Execution on the server running velocity.js. This compromises confidentiality, integrity, and availability of the affected system. The severity is high given the CVSS score of 8.3. No known exploits in the wild have been reported so far.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, avoid rendering Velocity templates from untrusted sources to prevent exploitation. Monitor shepherdwind project communications for updates on patches or mitigations.