CVE-2026-33508

Description

### Impact 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. Deployments are affected when the LiveQuery WebSocket endpoint is reachable by untrusted clients. ### Patches The fix adds query condition depth validation to the LiveQuery subscription handler, enforcing the same `requestComplexity.queryDepth` limit that already protects REST API queries. ### Workarounds There is no known workaround other than upgrading.

How to fix CVE-2026-33508

To remediate CVE-2026-33508, upgrade the affected package to a fixed version below.

• —upgrade to 8.6.56 or later
• —upgrade to 9.6.0-alpha.45 or later

Is CVE-2026-33508 being exploited?

Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• from 0, < 8.6.56, >= 9.0.0, < 9.6.0
• >= 9.0.0, < 9.6.0-alpha.45

CVSS scores

References (7)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2026-33508
• PATCHgithub.com/parse-community/parse-server
• WEBgithub.com/parse-community/parse-server/commit/060d27053fb0fadf613c25aabab7fe0c82b7a899
• WEBgithub.com/parse-community/parse-server/commit/2126fe4e12f9b399dc6b4b6a3fa70cb1825f159b