CVE-2019-19507
MEDIUMCVE-2019-19507 is a medium-severity (CVSS 5.3) Improper Authentication vulnerability in jpv. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2019-19507 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Validation bypass is possible in Json Pattern Validator
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.
jpvnpmDescription
In jpv (aka Json Pattern Validator) before 2.1.1, compareCommon() can be bypassed because certain internal attributes can be overwritten via a conflicting name, as demonstrated by 'constructor': {'name':'Array'}. This affects validate(). Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | jpv | all versions | 2.1.1 |
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 jpv. 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 jpv to 2.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-19507 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 CVE-2019-19507 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 CVE-2019-19507. 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-2019-19507 in your dependencies?
O3 detects CVE-2019-19507 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.