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GHSA-4x5r-pxfx-6jf8: @babel/core: Arbitrary File Read via sourceMappingURL Comment

lowCVSS 3.2CVE-2026-49356
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.

Details

Source
GitHub Security Advisories (INTL · database · site)
Severity
low — CVSS 3.2
Published
2026-06-15
Last updated
2026-07-15
Exploitation
Not in CISA KEV at last sync

Original advisory: https://github.com/advisories/GHSA-4x5r-pxfx-6jf8

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Referenced CVEs

CVECSIRTS overviewExternal
CVE-2026-49356coverage & exploitation statusNVD · CVE.org

Same CVEs, other sources

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