@babel/core: Arbitrary File Read via sourceMappingURL Comment (CVE-2026-49356)
A vulnerability in @babel/core prior to version 7.29.6 allows an attacker who controls input source code and can read the output source code to read arbitrary source map files on the system running Babel. This requires the attacker to know the path of the source map file they want to access. Users compiling only trusted code are not affected. The issue is fixed in @babel/core version 7.29.6 and later.
AI Analysis
Technical Summary
The vulnerability in @babel/core (CVE-2026-49356) permits arbitrary file read of source map files via the sourceMappingURL comment when maliciously crafted input source code is compiled. The attack requires three conditions: attacker control of input source code, ability to read the output source code, and knowledge of the source map file path. This can lead to unintended disclosure of source map files on the system running Babel. The vulnerability is addressed in versions 7.29.6 and 8.0.0-rc.6.
Potential Impact
An attacker meeting all required conditions can read arbitrary source map files on the system running Babel, potentially exposing sensitive source code information. There is no impact on integrity or availability. Users compiling only trusted code are not impacted.
Mitigation Recommendations
Upgrade @babel/core to version 7.29.6 or later. Alternatively, callers can mitigate without upgrading by setting the Babel option inputSourceMap to false, or by manually validating and controlling the sourceMappingURL comment in input source code before passing it to Babel.
@babel/core: Arbitrary File Read via sourceMappingURL Comment (CVE-2026-49356)
Description
A vulnerability in @babel/core prior to version 7.29.6 allows an attacker who controls input source code and can read the output source code to read arbitrary source map files on the system running Babel. This requires the attacker to know the path of the source map file they want to access. Users compiling only trusted code are not affected. The issue is fixed in @babel/core version 7.29.6 and later.
CVSS v3.1
Score 3.2low
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in @babel/core (CVE-2026-49356) permits arbitrary file read of source map files via the sourceMappingURL comment when maliciously crafted input source code is compiled. The attack requires three conditions: attacker control of input source code, ability to read the output source code, and knowledge of the source map file path. This can lead to unintended disclosure of source map files on the system running Babel. The vulnerability is addressed in versions 7.29.6 and 8.0.0-rc.6.
Potential Impact
An attacker meeting all required conditions can read arbitrary source map files on the system running Babel, potentially exposing sensitive source code information. There is no impact on integrity or availability. Users compiling only trusted code are not impacted.
Mitigation Recommendations
Upgrade @babel/core to version 7.29.6 or later. Alternatively, callers can mitigate without upgrading by setting the Babel option inputSourceMap to false, or by manually validating and controlling the sourceMappingURL comment in input source code before passing it to Babel.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-4x5r-pxfx-6jf8
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-49356"]
- Ecosystems
- ["npm"]
- Database Specific Severity
- LOW
- Cvss Version
- 3.1
Threat ID: 6a58b41068715ace43d67d46
Added to database: 07/16/2026, 10:36:00 UTC
Last enriched: 07/16/2026, 10:52:13 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 57
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