CVE-2026-33508
Parse Server: LiveQuery subscription query depth bypass
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.
Blast Radius
parse-server📦parse-serverReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.56 and 9.6.0-alpha.45, Parse Server's LiveQuery component does not enforce the requestComplexity.queryDepth configuration setting when processing WebSocket subscription requests. An attacker can send a subscription with deeply nested logical operators, causing excessive recursion and CPU consumption that degrades or disrupts service availability. This issue has been patched in versions 8.6.56 and 9.6.0-alpha.45.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | parse-server | ≥ 9.0.0&&< 9.6.0-alpha.45 | 9.6.0-alpha.45 |
| 📦npm | parse-server | all versions | 8.6.56 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for parse-server. 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 parse-server to 9.6.0-alpha.45 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33508 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-2026-33508 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-2026-33508. 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-2026-33508 in your dependencies?
O3 detects CVE-2026-33508 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.