Prototype Pollution Vulnerability in Velocity.js by Shepherdwind
CVE-2026-44966

8.3HIGH

Key Information:

Vendor

Shepherdwind

Status
Velocity.js
Vendor
CVE Published:
26 May 2026

What is CVE-2026-44966?

A critical prototype pollution vulnerability has been identified in Velocity.js, a JavaScript implementation of the Apache Velocity template engine. This vulnerability is present in version 2.1.5 and earlier. When processing #set directives within Velocity templates, if an attacker gains control over the template, they may exploit this weakness to alter Object.prototype. Such modifications can lead to significant security issues, including Denial of Service (DoS) attacks or Remote Code Execution (RCE), depending on the specific environment of the server hosting the application. Developers using affected versions should prioritize patching to safeguard against potential exploitation.

Affected Version(s)

velocity.js <= 2.1.5

References

https://github.com/shepherdwind/velocity.js/security/advi...
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CVSS V3.1

Score:
8.3
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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