CVE-2026-33943
8.8 · HIGHOverview
CVE-2026-33943 is a high-severity vulnerability affecting capricorn86 happy_dom. It was published on March 27, 2026 and has a CVSS 3.1 base score of 8.8 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.8, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. In versions 15.10.0 through 20.8.7, a code injection vulnerability in `ECMAScriptModuleCompiler` allows an attacker to achieve Remote Code Execution (RCE) by injecting arbitrary JavaScript expressions inside `export { }` declarations in ES module scripts processed by happy-dom. The compiler directly interpolates unsanitized content into generated code as an executable expression, and the quote filter does not strip backticks, allowing template literal-based payloads to bypass sanitization. Version 20.8.8 fixes the issue.
Remediation
Check the references section for vendor advisories and patches from capricorn86. Update happy_dom to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| capricorn86 | happy_dom | >= 15.10.0, < 20.8.8 | Affected |
References
Frequently Asked Questions
What is CVE-2026-33943?
CVE-2026-33943 is a high-severity vulnerability affecting capricorn86 happy_dom. It was published on March 27, 2026 and has a CVSS 3.1 base score of 8.8 (HIGH).
How severe is CVE-2026-33943?
This vulnerability has a CVSS 3.1 base score of 8.8, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-33943?
Check the references section for vendor advisories and patches from capricorn86. Update happy_dom to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-33943?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-33943 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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