# CVE-2026-115895: Happy DOM: Incomplete fix for CVE-2026-33943: unsanitized import alias leads to host code execution


- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** CLSA-2026-1793113520, CLSA-2026-1793122387, GHSA-834v-8h66-3h79

## 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 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-115895?

2 open source packages ship an affected version, including happy-dom.


| Package | Ecosystem | 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-115895 and fix it if it is affected.

What it is: CVE-2026-115895 is a high-severity vulnerability in capricorn86 happy-dom, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-115895 in the wild and no public exploit code.

Affected packages and fixed versions:
- happy-dom (npm): affected from 17.0.0; fixed in 21.0.4
- happy-dom (npm): affected from 17.0.0; fixed in 21.0.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-115895/ (Markdown: https://insights.sbomify.com/CVE-2026-115895/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-115895
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-115895
- OSV: https://osv.dev/vulnerability/CVE-2026-115895

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-115895/
Summaries are generated and may contain mistakes; the official description above is the record.