NPM · JULY 2026 · EARLY WARNING

Potential Remote Code Execution in velocityjs v2.1.6: Early Warning

EARLY WARNING · UNCONFIRMED. This page describes a developing threat that 0Day surfaced from early signals and has not yet independently confirmed. Details may change. Always verify against the primary sources before acting.
GHSA-7GFH-X38P-PRH3GHSA-J658-C2GF-X6PQSeverity: HIGH

An early warning has been issued regarding a potential Remote Code Execution (RCE) vulnerability in velocityjs version 2.1.6. This vulnerability reportedly allows arbitrary code execution on servers rendering attacker-controlled Velocity templates.

What happened

According to the GitHub Security Advisory GHSA-7gfh-x38p-prh3, velocityjs version 2.1.6 appears to contain a critical vulnerability that bypasses a previous fix for a prototype pollution issue (tracked as GHSA-j658-c2gf-x6pq). This bypass enables remote code execution via property-read to the Function constructor.

The vulnerability is under investigation, and it is recommended that any application utilizing server-side rendering of Velocity templates be reviewed for potential exposure. Specifically, applications that render templates controlled by attackers may be at risk.

At this time, a patched version of velocityjs is not yet available. Engineers are advised to monitor updates from the primary sources and prepare to upgrade once a fix is released. Further details and confirmations should be sought from the GitHub Advisory Database entries GHSA-7gfh-x38p-prh3 and GHSA-j658-c2gf-x6pq.

How 0Day mitigates this

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