CVE-2026-30946
Parse Server affected by denial-of-service via unbounded query complexity in REST and GraphQL API
Description
### Impact An unauthenticated attacker can exhaust Parse Server resources (CPU, memory, database connections) through crafted queries that exploit the lack of complexity limits in the REST and GraphQL APIs. All Parse Server deployments using the REST or GraphQL API are affected. ### Patches The vulnerability is fixed by introducing configurable request complexity limits via the `requestComplexity` server option with the following keys: - `subqueryDepth`: Maximum nesting depth for `$inQuery`, `$notInQuery`, `$select`, `$dontSelect` - `includeDepth`: Maximum depth of dot-separated `include` paths - `includeCount`: Maximum number of `include` fields per query - `graphQLDepth`: Maximum depth of GraphQL field selections - `graphQLFields`: Maximum number of field selections in a GraphQL query Requests using master key or maintenance key bypass these limits. Set any property to `-1` to disable that specific limit. In versions `8.6.15` and `9.5.2-alpha.2`, these limits were enabled by default. This unintentionally introduced a breaking change for some applications with legitimate complex queries. In versions `8.6.46` and `9.6.0-alpha.22`, the defaults were changed to `-1` (disabled) to restore backwards compatibility. The limits remain available as configuration options. To mitigate the vulnerability, upgrade to a patched version and set each `requestComplexity` property to a value appropriate for your application. ### Workarounds There is no known workaround. ### References - GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-cmj3-wx7h-ffvg - Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.2-alpha.2 - Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.15
How to fix CVE-2026-30946
To remediate CVE-2026-30946, upgrade the affected package to a fixed version below.
- —upgrade to 8.6.15 or later
- —upgrade to 8.6.15 or later
Is CVE-2026-30946 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.