CVE-2026-49356
@babel/core: Arbitrary File Read via sourceMappingURL Comment
Summary
## Impact Using `@babel/core` to compile maliciously crafted code can allow ab attacker to read any source map from the system that is running Babel, if these conditions are _all_ true: - the attacker controls the input source code - the attacker can read the output source code - the attacker knows the path of the source map file that they want to read **Users that only compile trusted code are not impacted.** ## Patches The vulnerability has been fixed in `@babel/[email protected]` and `@babel/[email protected]`. ## Workarounds Callers can mitigate the issue without upgrading by setting [`inputSourceMap: false`](https://babeljs.io/docs/options#inputsourcemap) in their Babel options. Callers can also manually extract the `#sourceMappingURL` comment from the input source code, validate whether the source map that it links to is allowed to be read, and if it is pass an object to `inputSourceMap` (passing `false` when it's not). ## Credits Thanks Teodor-Cristian Radoi for reporting the vulnerability.
Affected packages
| Ecosystem | Package | Affected versions | Fixed versions |
|---|---|---|---|
| npm | @babel/core | — | 7.29.6 |
References
Includes data from OSV.dev.
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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.