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Vulnerability · Published Aug 13, 2026 · Assigned by GitHub_M

CVE-2026-73649Velocity.js: Remote Code Execution via property-read to Function constructor (bypass of CVE-2026-44966 fix)

Critical 9.8

In plain English

A critical-severity code injection in velocity.js from shepherdwind. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.7%top 45.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npmvelocityjs2.1.7GHSA-7gfh-x38p-prh3

Affected products (as reported)

VendorProductVersions
shepherdwind velocity.js < 2.1.7

Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References