Uncontrolled Recursion in Parse Server - CVE-2026-33508
Published: April 6, 2026
Vulnerability identifier: #VU125007
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33508
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled recursion in the LiveQuery subscription handler when processing WebSocket subscription requests with deeply nested logical operators. A remote attacker can send a specially crafted subscription request to cause a denial of service.
Deployments are affected when the LiveQuery WebSocket endpoint is reachable by untrusted clients.
Affected software
Parse Server
How to mitigate CVE-2026-33508
Install security update from vendor's website.
Parse Server - addressed in versions 8.6.56, 9.6.0 alpha.45