CVE-2026-119569: Parse Server 9.0.0 before 9.10.5-alpha.9 Prototype Pollution Denial of Service

Parse Server before 8.6.108 and 9.0.0 before 9.10.5-alpha.9 contains a prototype pollution vulnerability because user-controlled keys are expanded into objects without own-property checks. Clients with class write access can send dot notation field keys or ACL entry names matching built-in object members to corrupt built-in functions, causing all requests to fail until server restart.