CVE-2020-35149 is a medium-severity (CVSS 5.3) vulnerability in mquery. O3 Security confirms whether CVE-2020-35149 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Code Injection in mquery
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.
mquerynpmDescription
lib/utils.js in mquery before 3.2.3 allows a pollution attack because a special property (e.g., proto) can be copied during a merge or clone operation.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mquery | all versions | 3.2.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mquery. 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 mquery to 3.2.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-35149 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-2020-35149 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-2020-35149. 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.
The affected version of mquery is a dependency of the mongoose library. The exploitation of this vulnerability requires authenticated access, consequently, the CVSSv3 score for RHACM is lower than the score of the flaw.
Frequently Asked Questions
Is CVE-2020-35149 in your dependencies?
O3 detects CVE-2020-35149 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.