CVE-2026-44728 — @babel/plugin-transform-m…
HIGHCVE-2026-44728 is a high-severity (CVSS 8.2) Code Injection vulnerability in @babel/plugin-transform-modules-systemjs. A fix is available for @babel/plugin-transform-modules-systemjs — see the affected versions and patch details below.
Improper Control of Generation of Code when compiling specifically crafted malicious code with @babel/plugin-transform-modules-systemjs
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-44728.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@babel/plugin-transform-modules-systemjsnpmDescription
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-envwhen using themodules: "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.
Patches
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.
Workarounds
- Pin
@babel/parserto 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-systemjsto 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @babel/plugin-transform-modules-systemjs | ≥ 7.12.0&&< 7.29.4 | 7.29.4npm install @babel/plugin-transform-modules-systemjs@7.29.4 |
| 📦npm | @babel/plugin-transform-modules-systemjs | ≥ 8.0.0-alpha.0&&< 8.0.0-alpha.13 | 8.0.0-alpha.13npm install @babel/plugin-transform-modules-systemjs@8.0.0-alpha.13 |
Affected Products
babelbabelDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @babel/plugin-transform-modules-systemjs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @babel/plugin-transform-modules-systemjs to 7.29.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44728 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2026-44728 in your dependencies?
Find it across npm, including transitive dependencies.