Arbitrary file read via unchecked sourceMappingURL path
Published Jun 22, 2026 · Updated Jun 22, 2026
Path traversal in @babel/core before 7.29.6 and 8.0.0-alpha.0 through 8.0.0-rc.5 allows attackers to read local source maps. The input source-map loader follows a path from an untrusted sourceMappingURL comment without first restricting which local map file may be loaded. Exploitation requires control of compiler input, knowledge of the target map path, and access to the generated output; trusted-only compilation is unaffected.
Summary
What happened
Path traversal in @babel/core before 7.29.6 and 8.0.0-alpha.0 through 8.0.0-rc.5 allows attackers to read local source maps. The input source-map loader follows a path from an untrusted sourceMappingURL comment without first restricting which local map file may be loaded. Exploitation requires control of compiler input, knowledge of the target map path, and access to the generated output; trusted-only compilation is unaffected.
The record
- CVE
- CVE-2026-49356
- Published
- Jun 22, 2026
- Updated
- Jun 22, 2026
- Vendor
- Babel
- Product
- Babel
- Classifications
- CWE-200, CWE-22, T1005
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 22, 2026CVE publishedPublication date reported by the CVE source.
- Jun 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 7.29.6
- Affected versionversion=>= 8.0.0-alpha.0, < 8.0.0-rc.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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