Vulnerability · Published May 26, 2026 · Assigned by GitHub_M
CVE-2026-44966Velocity.js: Prototype Pollution in #set path assignment
High 8.3
In plain English
A high-severity prototype pollution in velocity.js from shepherdwind. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).
Official description
Velocity.js is a JavaScript implementation of the Apache Velocity template engine. In 2.1.5 and earlier, a prototype pollution vulnerability was discovered in velocityjs. This issue occurs during the processing of #set directives in Velocity templates. If an application renders a template controlled by an attacker, it is possible to modify Object.prototype, potentially leading to Denial of Service (DoS) or Remote Code Execution (RCE) depending on the server environment.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | velocityjs | no fix listed | GHSA-j658-c2gf-x6pq |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| shepherdwind | velocity.js | <= 2.1.5 |
Weakness: CWE-1321 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L