CVE-2023-38704 is a high-severity (CVSS 8.1) Improper Input Validation vulnerability in import-in-the-middle. A fix is available for import-in-the-middle — see the affected versions and patch details below.
import-in-the-middle allows unsanitized user controlled input in module generation
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 CVE-2023-38704.
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
CVE-2023-38704 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.
import-in-the-middlenpmDescription
import-in-the-middle is a module loading interceptor specifically for ESM modules. The import-in-the-middle loader works by generating a wrapper module on the fly. The wrapper uses the module specifier to load the original module and add some wrapping code. Prior to version 1.4.2, it allows for remote code execution in cases where an application passes user-supplied input directly to the import() function. This vulnerability has been patched in import-in-the-middle version 1.4.2.
Some workarounds are available. Do not pass any user-supplied input to import(). Instead, verify it against a set of allowed values. If using import-in-the-middle, directly or indirectly, and support for EcmaScript Modules is not needed, ensure that no options are set, either via command-line or the NODE_OPTIONS environment variable, that would enable loader hooks.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | import-in-the-middle | all versions | 1.4.2npm install import-in-the-middle@1.4.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for import-in-the-middle, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update import-in-the-middle to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-38704 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 CVE-2023-38704 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-38704. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-38704 in your dependencies?
O3 Security finds CVE-2023-38704 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.