CVE-2026-44966
Prototype Pollution in Velocity.js Template Engine
Publication date: 2026-05-26
Last updated on: 2026-05-26
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| apache | velocity | to 2.1.5 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-1321 | The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
Velocity.js is a JavaScript implementation of the Apache Velocity template engine. In versions 2.1.5 and earlier, there is a prototype pollution vulnerability that occurs during the processing of #set directives in Velocity templates. If an attacker controls the template being rendered by an application, they can modify the Object.prototype, which is a fundamental JavaScript object. This manipulation can lead to serious security issues.
How can this vulnerability impact me? :
Exploiting this vulnerability can allow an attacker to cause Denial of Service (DoS) or even Remote Code Execution (RCE) depending on the server environment where the application is running. This means an attacker could disrupt the availability of the service or execute arbitrary code remotely, potentially compromising the entire system.