CVE-2026-34363 — parse-server
Fix: parse-community/parse-server@5834e29CVE-2026-34363 is a CWE-362 vulnerability in parse-server. A fix is available for parse-server — see the affected versions and patch details below.
Parse Server: LiveQuery protected field leak via shared mutable state across concurrent subscribers
Exploitation Status
No confirmed exploitation observed yet
- 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-2026-34363.
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.
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. Prior to versions 8.6.65 and 9.7.0-alpha.9, when multiple clients subscribe to the same class via LiveQuery, the event handlers process each subscriber concurrently using shared mutable objects. The sensitive data filter modifies these shared objects in-place, so when one subscriber's filter removes a protected field, subsequent subscribers may receive the already-filtered object. This can cause protected fields and authentication data to leak to clients that should not see them, or cause clients that should see the data to receive an incomplete object. Additionally, when an afterEvent Cloud Code trigger is registered, one subscriber's trigger modifications can leak to other subscribers through the same shared mutable state. Any Parse Server deployment using LiveQuery with protected fields or afterEvent triggers is affected when multiple clients subscribe to the same class. This issue has been patched in versions 8.6.65 and 9.7.0-alpha.9.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | parse-server | ≥ 9.0.0&&< 9.7.0-alpha.9 | 9.7.0-alpha.9npm install parse-server@9.7.0-alpha.9 |
| 📦npm | parse-server | all versions | 8.6.65npm install parse-server@8.6.65 |
Detection & 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 9.7.0-alpha.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34363 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-2026-34363 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-34363. 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-2026-34363 in your dependencies?
O3 Security finds CVE-2026-34363 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.