CVE-2026-73649
Velocity.js: Remote Code Execution via property-read to Function constructor (bypass of CVE-2026-44966 fix)
Record summary
CVE-2026-73649 has a selected CVSS score of 9.8 (critical).
Description
Velocity.js is a JavaScript implementation of the Apache Velocity template engine. Prior to 2.1.7, the earlier fix for CVE-2026-44966 filtered constructor, __proto__, and prototype only in the #set assignment handler in src/compile/set.ts, while property-read expressions in src/compile/references.ts remained unfiltered. The getReferences() flow called getAttributes(), whose property access allowed an attacker-controlled template to traverse constructor.constructor to the JavaScript Function constructor. The #set handler validated only the assignment target and did not inspect the right-hand property-read expression, allowing arbitrary shell commands, environment-variable access, cloud-credential access, and internal-network access in the server process. This issue is fixed in version 2.1.7.
Affected products and versions
2| Product | Source | Version range | Status |
|---|---|---|---|
velocity.jsBrowse shepherdwind / velocity.js | CVE List | < 2.1.7 | affected |
velocityjsBrowse npm / velocityjs | GitHub Advisory | Before 2.1.7 · Fixed in 2.1.7 | affected |