CVE-2026-44728

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.

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, 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.

Untrusted input is evaluated as executable code within the application's runtime environment. Typical impact: arbitrary code execution within the application's privilege context.

CVE-2026-44728 has a CVSS score of 8.2 (High). The vector is requires local access, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (7.29.4, 8.0.0-alpha.13); upgrading removes the vulnerable code path.

Kodem intelligence

The vulnerability has been fixed in @babel/[email protected].

Babel also released @babel/[email protected], updating its @babel/plugin-transform-modules-systemjs dependency, to simplify forcing the update if you are using @babel/preset-env directly.

1. What is CVE-2026-44728? CVE-2026-44728 is a high-severity code injection vulnerability in @babel/plugin-transform-modules-systemjs (npm), affecting versions >= 7.12.0, <= 7.29.3. It is fixed in 7.29.4, 8.0.0-alpha.13. Untrusted input is evaluated as executable code within the application's runtime environment.
2. How severe is CVE-2026-44728? CVE-2026-44728 has a CVSS score of 8.2 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of @babel/plugin-transform-modules-systemjs are affected by CVE-2026-44728? @babel/plugin-transform-modules-systemjs (npm) versions >= 7.12.0, <= 7.29.3 is affected.
4. Is there a fix for CVE-2026-44728? Yes. CVE-2026-44728 is fixed in 7.29.4, 8.0.0-alpha.13. Upgrade to this version or later.
5. Is CVE-2026-44728 exploitable, and should I be worried? Whether CVE-2026-44728 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-44728 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-44728?
   • Upgrade @babel/plugin-transform-modules-systemjs to 7.29.4 or later
   • Upgrade @babel/plugin-transform-modules-systemjs to 8.0.0-alpha.13 or later