CVE-2021-32819: Squirrelly is a template engine implemented in JavaScript that works out of the box with ExpressJS. Squirrelly mixes pure template data with engine co...

Description

Squirrelly is a template engine implemented in JavaScript that works out of the box with ExpressJS. Squirrelly mixes pure template data with engine configuration options through the Express render API. By overwriting internal configuration options remote code execution may be triggered in downstream applications. This issue is fixed in version 9.0.0. For complete details refer to the referenced GHSL-2021-023.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

59.84%

99.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-200

Affected Software

Vendor	Product	Versions
Squirrelly	Squirrelly	8.0.8

References

Timeline

Published: May 14, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32819?

Squirrelly is a template engine implemented in JavaScript that works out of the box with ExpressJS. Squirrelly mixes pure template data with engine configuration options through the Express render API. By overwriting internal configuration options remote code execution may be triggered in downstream applications. This issue is fixed in version 9.0.0. For complete details refer to the referenced GHSL-2021-023.

How severe is CVE-2021-32819?

CVE-2021-32819 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 59.84% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32819?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.