Low

@babel/core: Arbitrary File Read via sourceMappingURL Comment

  • Disclosed: 15.06.2026
  • Updated: 11.10.2026 10:22

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/core@7.29.6 and @babel/core@8.0.0-rc.6.

Workarounds

Callers can mitigate the issue without upgrading by setting inputSourceMap: false 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 software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package @babel/core >= 8.0.0-alpha.0, < 8.0.0-rc.6, < 7.29.6 8.0.0-rc.6, 7.29.6

References

CVSS score 3.2/10
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N
Weakness (CWE)
CWE-200, CWE-22
Platform
npm
Package
@babel/core
Disclosed
15.06.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-4x5r-pxfx-6jf8 - CC BY 4.0

Vulnerability history: @babel/core

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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