CVE-2026-115895 Happy DOM: Incomplete fix for CVE-2026-33943: unsanitized import alias leads to host code execution
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-115895?
CVE-2026-115895 is a high-severity vulnerability in capricorn86 happy-dom, published on 23 Oct 2026.
Official description
Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. From 17.0.0 until 21.0.4, packages/happy-dom/src/module/ECMAScriptModuleCompiler.ts accepts a named ESM import alias without validating that it is a JavaScript binding identifier before inserting it into a generated destructuring binding. With enableJavaScriptEvaluation enabled, attacker-controlled HTML or module source can use an invalid alias that becomes a valid default initializer after compilation, causing the generated JavaScript to execute in the Node.js host process. The demonstrated reachable path uses a JSON module import attribute, which prevents the malicious alias from being emitted again in a later ESM circular-import assignment and keeps the generated function syntactically valid. This incomplete fix for CVE-2026-33943 is a distinct residual path because the earlier remediation validated the local export importName path but not the named-import alias. This issue is fixed in version 21.0.4.
Weakness: CWE-94
Which versions are affected by CVE-2026-115895?
2 open source packages ship an affected version, including happy-dom.
| Package | Affected | Fixed in |
|---|---|---|
happy-dom npm | From 17.0.0 | 21.0.4 |
happy-dom npm | From 17.0.0 | 21.0.4 |
How do I fix CVE-2026-115895?
Upgrade happy-dom to 21.0.4 or later.
Is CVE-2026-115895 being exploited?
There is no known exploitation of CVE-2026-115895 in the wild and no public exploit code.
Sources
Also known as CLSA-2026-1793113520, CLSA-2026-1793122387, GHSA-834v-8h66-3h79.