Answer in brief
CVE-2026-49356 records a Low severity (CVSS 3.2) vulnerability in @babel/core: Arbitrary File Read via sourceMappingURL Comment. The current sources do not mark it as known exploited. The current feed maps @babel/core (npm), @babel/core (npm), @babel/core (npm), @babel/core (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps @babel/core (npm), @babel/core (npm), @babel/core (npm), @babel/core (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| @babel/corenpm | >=8.0.0-alpha.0,<8.0.0-rc.5 | 8.0.0-rc.6 |
| @babel/corenpm | <=7.29.0 | 7.29.6 |
| @babel/corenpm | >=8.0.0-alpha.0 <8.0.0-rc.6 | 8.0.0-rc.6 |
| @babel/corenpm | >=0 <7.29.6 | 7.29.6 |
Published upstream
Jun 15, 2026
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Jun 19, 2026
## 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.
Quoted source text, attributed separately from HOL analysis.