CVE-2026-73649 Velocity.js: Remote Code Execution via property-read to Function constructor (bypass of CVE-2026-44966 fix)
Attackers can execute arbitrary code by exploiting unfiltered property reads in Velocity.js templates, bypassing previous security fixes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-73649?
CVE-2026-73649 is a critical code injection vulnerability in shepherdwind velocity.js, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-94
Which versions are affected by CVE-2026-73649?
2 open source packages ship an affected version, including velocityjs.
| Package | Affected | Fixed in |
|---|---|---|
velocityjs npm | All versions | 2.1.7 |
velocityjs npm | All versions | 2.1.7 |
How do I fix CVE-2026-73649?
Upgrade velocityjs to 2.1.7 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-73649 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73649 exists.
Sources
Also known as GHSA-7gfh-x38p-prh3, ROOT-APP-NPM-GHSA-7gfh-x38p-prh3.