GHSA-xgh6-85xh-479p
GHSA-xgh6-85xh-479p is a security vulnerability in npm-user-validate. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-xgh6-85xh-479p is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Regular Expression Denial of Service in npm-user-validate
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.
npm-user-validatenpmDescription
npm-user-validate before version 1.0.1 is vulnerable to a Regular Expression Denial of Service (REDos). The regex that validates user emails took exponentially longer to process long input strings beginning with @ characters.
Impact
The issue affects the email function. If you use this function to process arbitrary user input with no character limit the application may be susceptible to Denial of Service.
Patches
The issue is patched in version 1.0.1 by improving the regular expression used and also enforcing a 254 character limit.
Workarounds
Restrict the character length to a reasonable degree before passing a value to .emal(); Also, consider doing a more rigorous sanitizing/validation beforehand.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | npm-user-validate | all versions | 1.0.1 |
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 npm-user-validate. 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 npm-user-validate to 1.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xgh6-85xh-479p 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-xgh6-85xh-479p 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-xgh6-85xh-479p. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
In Red Hat Enterprise Linux 8 and Software Collections, `npm-user-validate` is used exclusively for `npm`. As a result, this vulnerability is considered Low in such a context. In OpenShift Container Platform (OCP) 3.11 and 4.4 the kibana package has been marked Low (similar to RHEL8) as it is primarily used for npm…
Frequently Asked Questions
Is GHSA-xgh6-85xh-479p in your dependencies?
O3 detects GHSA-xgh6-85xh-479p across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.