CVE-2026-32594 in parse-server
Summary
by MITRE • 03/16/2026
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.40 and 9.6.0-alpha.14, the GraphQL WebSocket endpoint for subscriptions does not pass requests through the Express middleware chain that enforces authentication, introspection control, and query complexity limits. An attacker can connect to the WebSocket endpoint and execute GraphQL operations without providing a valid application or API key, access the GraphQL schema via introspection even when public introspection is disabled, and send arbitrarily complex queries that bypass configured complexity limits. This vulnerability is fixed in 8.6.40 and 9.6.0-alpha.14.
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Analysis
by VulDB Data Team • 03/21/2026
The vulnerability described in CVE-2026-32594 affects Parse Server versions prior to 8.6.40 and 9.6.0-alpha.14, representing a critical security flaw in the GraphQL WebSocket endpoint implementation. This issue stems from the improper handling of authentication and access control mechanisms within the subscription endpoint, creating a significant attack vector for malicious actors seeking to exploit the backend infrastructure. The vulnerability specifically impacts the GraphQL WebSocket endpoint used for real-time subscriptions, which should normally be protected by the same middleware chain that secures HTTP endpoints but fails to enforce these protections in the WebSocket context.
The technical flaw manifests in the failure to pass WebSocket requests through the Express middleware chain that enforces essential security controls including authentication verification, introspection restrictions, and query complexity limits. This architectural oversight allows unauthorized access to GraphQL operations through the WebSocket interface, bypassing the standard authentication mechanisms that would normally require valid application or API keys for access. The vulnerability enables attackers to connect directly to the WebSocket endpoint and execute GraphQL operations without proper authorization, effectively circumventing the authentication layer that should protect sensitive backend operations.
The operational impact of this vulnerability is substantial, as it provides attackers with unrestricted access to GraphQL schema introspection capabilities even when public introspection has been disabled through configuration. This means that malicious actors can discover and map the complete GraphQL schema structure, potentially identifying sensitive data endpoints, relationships, and query patterns that could be exploited for further attacks. Additionally, the bypass of query complexity limits allows attackers to submit arbitrarily complex queries that can overwhelm system resources, potentially leading to denial-of-service conditions and performance degradation. The combination of these factors creates a dangerous attack surface that can be leveraged for both information disclosure and system disruption.
This vulnerability aligns with CWE-284 Access Control Issues, specifically representing inadequate access controls in a WebSocket endpoint that should be protected by the same authentication mechanisms as HTTP endpoints. The issue also relates to CWE-400 Uncontrolled Resource Consumption, as the bypass of query complexity limits can lead to resource exhaustion through maliciously crafted queries. From an ATT&CK framework perspective, this vulnerability maps to T1071.004 Application Layer Protocol: GraphQL, where adversaries can leverage GraphQL endpoints for reconnaissance and data extraction. The vulnerability also connects to T1566 Impersonation, as attackers can impersonate legitimate users through the bypassed authentication mechanisms.
Mitigation strategies should focus on immediate deployment of the fixed versions 8.6.40 and 9.6.0-alpha.14, which properly integrate the WebSocket endpoint with the Express middleware chain to enforce authentication, introspection controls, and query complexity limits. Organizations should also implement additional monitoring and logging for WebSocket connections to detect anomalous access patterns and unauthorized attempts to connect to subscription endpoints. Network segmentation and access controls should be enforced to limit exposure of GraphQL endpoints to trusted internal networks only, while implementing rate limiting and query complexity monitoring to prevent resource exhaustion attacks. Regular security assessments should verify that all endpoints properly enforce the same security controls regardless of the communication protocol used.