GHSA-f38p-c2gq-4pmr
HIGHGHSA-f38p-c2gq-4pmr is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in schema-inspector. 3 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-f38p-c2gq-4pmr is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Regular Expression Denial-of-Service in npm schema-inspector
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.
schema-inspectornpmDescription
Impact
What kind of vulnerability is it? Who is impacted?
Email address validation is vulnerable to a denial-of-service attack where some input (for example a@0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.) will freeze the program or web browser page executing the code. This affects any current schema-inspector users using any version to validate email addresses. Users who do not do email validation, and instead do other types of validation (like string min or max length, etc), are not affected.
Patches
Has the problem been patched? What versions should users upgrade to? Users should upgrade to version 2.0.0, which uses a regex expression that isn't vulnerable to ReDoS. The new regex expression is more limited in what it can check, so it is more flexible than the one used before. Therefore, this was a new major version instead of a new patch version to warn people upgrading that they should make sure the email validation still works for their use case.
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading? If a user chooses to not upgrade, the only known workaround would be to stop using the email validation feature in the library. The user could, for example, accept the email address into their system but save it in a "not yet validated" state in their system until a verification email is sent to it (to determine whether the email is valid and belongs to the form submitter). Note that this is the preferred way of validating email addresses anyways.
References
Are there any links users can visit to find out more? https://gist.github.com/mattwelke/b7f42424680a57b8161794ad1737cd8f
For more information
If you have any questions or comments about this advisory, you can create an issue in this repository.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | schema-inspector | all versions | 2.0.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for schema-inspector. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update schema-inspector to 2.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f38p-c2gq-4pmr 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 pinpoints whether GHSA-f38p-c2gq-4pmr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-f38p-c2gq-4pmr. 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-f38p-c2gq-4pmr in your dependencies?
O3 detects GHSA-f38p-c2gq-4pmr across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.