CVE-2021-32818 — haml-coffee
MEDIUMCVE-2021-32818 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in haml-coffee. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
Insecure template handling in haml-coffee
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-32818 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
haml-coffeenpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | haml-coffee | all versions | No fix |
Affected Products
haml-coffeehaml-coffee_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for haml-coffee, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of haml-coffee has shipped for CVE-2021-32818 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2021-32818 in your dependencies?
Find it across npm, including transitive dependencies.