# CVE-2026-32732: XSS in @leanprover/unicode-input-component

> Attackers can execute arbitrary scripts in the VS Code Lean 4 extension via unescaped HTML in the unicode input component.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 13 Mar 2026
- **Updated:** 16 Mar 2026
- **Also known as:** GHSA-6ggm-pwr9-r5h2

## What is CVE-2026-32732?

CVE-2026-32732 is a cross-site scripting vulnerability in leanprover vscode-lean4, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Lean 4 VS Code Extension is a Visual Studio Code extension for the Lean 4 proof assistant. Projects that use @leanprover/unicode-input-component are vulnerable to an XSS exploit in 0.1.9 of the package and lower. The component re-inserted text in the input element back into the input element as unescaped HTML. The issue has been resolved in 0.2.0.

Weakness: CWE-80 (Improper Neutralization of Script-Related HTML Tags in a Web Page)

## Which versions are affected by CVE-2026-32732?

2 open source packages ship an affected version, including @leanprover/unicode-input-component.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@leanprover/unicode-input-component` | npm | All versions | 0.2.0 |
| `@leanprover/unicode-input-component` | npm | All versions | 0.2.0 |

## How do I fix CVE-2026-32732?

Upgrade @leanprover/unicode-input-component to 0.2.0 or later.

## Is CVE-2026-32732 being exploited?

There is no known exploitation of CVE-2026-32732 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32732 and fix it if it is affected.

What it is: CVE-2026-32732 is a cross-site scripting vulnerability in leanprover vscode-lean4, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-32732 in the wild and no public exploit code.

Affected packages and fixed versions:
- @leanprover/unicode-input-component (npm): affected all versions; fixed in 0.2.0
- @leanprover/unicode-input-component (npm): affected all versions; fixed in 0.2.0

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-2026-32732/ (Markdown: https://insights.sbomify.com/CVE-2026-32732/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32732
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32732
- OSV: https://osv.dev/vulnerability/CVE-2026-32732

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32732/
Summaries are generated and may contain mistakes; the official description above is the record.