CVE-2026-44728
@babel/plugin-transform-modules-systemjs generates arbitrary code when compiling malicious input
Description
### Impact Using Babel to compile code that was specifically crafted by an attacker can cause Babel to generate output code that executes arbitrary code. Known affected plugins are: - `@babel/plugin-transform-modules-systemjs` - `@babel/preset-env` when using the [`modules: "systemjs"` option](https://babel.dev/docs/babel-preset-env#modules), as it delegates to `@babel/plugin-transform-modules-systemjs` No other plugins under the `@babel` namespace are impacted. **Users that only compile trusted code are not impacted.** ### Patches The vulnerability has been fixed in `@babel/plugin-transform-modules-systemjs@7.29.4`. Babel also released `@babel/preset-env@7.29.5`, updating its `@babel/plugin-transform-modules-systemjs` dependency, to simplify forcing the update if you are using `@babel/preset-env` directly. ### Workarounds - Pin `@babel/parser` to v7.11.5. The downgrade will completely disable string module name parsing, but it would also disable other new language features and the build pipeline may fail as a result. Only do so if you are working on a legacy codebase and can not upgrade `@babel/plugin-transform-modules-systemjs` to v7.29.4. - Do not use the `modules: "systemjs"` option, migrate the codebase to native ES Modules or any other module formats. ### Credits Babel thanks Daniel Cervera for reporting the vulnerability.
How to fix CVE-2026-44728
To remediate CVE-2026-44728, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 7.29.4 or later
Is CVE-2026-44728 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0