CVE-2019-17426 is a critical-severity (CVSS 9.1) vulnerability in mongoose. A fix is available for mongoose — see the affected versions and patch details below.
Improper Input Validation in Automattic Mongoose
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-2019-17426 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 377,636 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.
mongoosenpmDescription
Automattic Mongoose through 5.7.4 allows attackers to bypass access control (in some applications) because any query object with a _bsontype attribute is ignored. For example, adding "_bsontype":"a" can sometimes interfere with a query filter. NOTE: this CVE is about Mongoose's failure to work around this _bsontype special case that exists in older versions of the bson parser (aka the mongodb/js-bson project).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mongoose | ≥ 5.0.0&&< 5.7.5 | 5.7.5npm install mongoose@5.7.5 |
| 📦npm | mongoose | all versions | 4.13.21npm install mongoose@4.13.21 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mongoose, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mongoose to 5.7.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-17426 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-2019-17426 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2019-17426. 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-2019-17426 in your dependencies?
O3 Security finds CVE-2019-17426 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.