GHSA-4x5r-pxfx-6jf8 — @babel/core
LOWGHSA-4x5r-pxfx-6jf8 is a low-severity (CVSS 3.2) Path Traversal vulnerability in @babel/core. A fix is available for @babel/core — see the affected versions and patch details below.
@babel/core: Arbitrary File Read via sourceMappingURL Comment
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-4x5r-pxfx-6jf8.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-4x5r-pxfx-6jf8 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@babel/corenpmDescription
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 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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @babel/core | ≥ 8.0.0-alpha.0&&< 8.0.0-rc.6 | 8.0.0-rc.6npm install @babel/core@8.0.0-rc.6 |
| 📦npm | @babel/core | all versions | 7.29.6npm install @babel/core@7.29.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @babel/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @babel/core to 8.0.0-rc.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4x5r-pxfx-6jf8 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-4x5r-pxfx-6jf8 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-4x5r-pxfx-6jf8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-4x5r-pxfx-6jf8 in your dependencies?
O3 Security finds GHSA-4x5r-pxfx-6jf8 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.