CVE-2021-32818: haml-coffee is a JavaScript templating solution. haml-coffee mixes pure template data with engine configuration options through the Express render API...

Description

haml-coffee is a JavaScript templating solution. haml-coffee mixes pure template data with engine configuration options through the Express render API. More specifically, haml-coffee supports overriding a series of HTML helper functions through its configuration options. A vulnerable application that passes user controlled request objects to the haml-coffee template engine may introduce RCE vulnerabilities. Additionally control over the escapeHtml parameter through template configuration pollution ensures that haml-coffee would not sanitize template inputs that may result in reflected Cross Site Scripting attacks against downstream applications. There is currently no fix for these issues as of the publication of this CVE. The latest version of haml-coffee is currently 1.14.1. For complete details refer to the referenced GHSL-2021-025.

Metrics

CVSS 3.1

5.4/10

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

EPSS Probability

0.70%

48.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Haml-Coffee Project	Haml-Coffee	<= 1.14.1

References

https://securitylab.github.com/advisories/GHSL-2021-025-haml-coffee/Third Party Advisory
https://www.npmjs.com/package/haml-coffeeExploit, Product
https://securitylab.github.com/advisories/GHSL-2021-025-haml-coffee/Third Party Advisory
https://www.npmjs.com/package/haml-coffeeExploit, Product

Timeline

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

Frequently Asked Questions

What is CVE-2021-32818?

haml-coffee is a JavaScript templating solution. haml-coffee mixes pure template data with engine configuration options through the Express render API. More specifically, haml-coffee supports overriding a series of HTML helper functions through its configuration options. A vulnerable application that passes user controlled request objects to the haml-coffee template engine may introduce RCE vulnerabilities. Additionally control over the escapeHtml parameter through template configuration pollution ensures that haml-coffee would not sanitize template inputs that may result in reflected Cross Site Scripting attacks against downstream applications. There is currently no fix for these issues as of the publication of this CVE. The latest version of haml-coffee is currently 1.14.1. For complete details refer to the referenced GHSL-2021-025.

How severe is CVE-2021-32818?

CVE-2021-32818 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.70% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32818?

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.