CVE-2022-39396 is a critical-severity (CVSS 9.8) CWE-1321 vulnerability in parse-server. EPSS puts its 30-day exploitation probability at 38.7% (99th percentile). A fix is available for parse-server — see the affected versions and patch details below.
Parse Server vulnerable to Remote Code Execution via prototype pollution in MongoDB BSON parser
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-39396.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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.
parse-servernpmDescription
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Versions prior to 4.10.18, and prior to 5.3.1 on the 5.X branch, are vulnerable to Remote Code Execution via prototype pollution. An attacker can use this prototype pollution sink to trigger a remote code execution through the MongoDB BSON parser. This issue is patched in version 5.3.1 and in 4.10.18. There are no known workarounds.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | parse-server | all versions | 4.10.18npm install parse-server@4.10.18 |
| 📦npm | parse-server | ≥ 5.0.0&&< 5.3.1 | 5.3.1npm install parse-server@5.3.1 |
Affected Products
parse-serverparseplatformDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for parse-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update parse-server to 4.10.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39396 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.
Frequently Asked Questions
Is CVE-2022-39396 in your dependencies?
Find it across npm, including transitive dependencies.