CVE-2025-64173 is an authentication bypass vulnerability identified in Apollo Router Core, a configurable graph router written in Rust that facilitates federated supergraphs using Apollo Federation 2. The vulnerability exists in versions prior to 1.61.12 and from 2.0.0-alpha.0 up to but not including 2.8.1. It stems from the router's incorrect handling of access control directives (@authenticated, @requiresScopes, @policy) on polymorphic GraphQL types—specifically, interface types and their implementing object types. When all implementations of an interface have the same access requirements, the router applies access control directives only to the interface types/fields and ignores those on the implementing object types/fields. This inconsistency allows unauthenticated queries to bypass intended access controls and retrieve sensitive data. The flaw is classified under CWE-288 (Authentication Bypass Using an Alternate Path or Channel). Exploitation requires no privileges or user interaction, making it a network-exploitable vulnerability with a CVSS v3.1 score of 7.5 (high severity). Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk to confidentiality as unauthorized data access can occur. The issue is resolved in Apollo Router versions 1.61.12 and 2.8.1. Organizations using Apollo Router with federated GraphQL schemas that define access control directives inconsistently on polymorphic types should consider themselves vulnerable until patched.

For European organizations, the impact of CVE-2025-64173 is primarily the unauthorized disclosure of sensitive data due to authentication bypass. Enterprises relying on Apollo Router for federated GraphQL APIs—common in modern microservices and cloud-native architectures—may inadvertently expose protected data fields if their schema directives are inconsistently applied. This can lead to data breaches, regulatory non-compliance (notably GDPR), reputational damage, and potential financial penalties. The vulnerability does not affect data integrity or availability but compromises confidentiality, which is critical for sectors handling personal or sensitive information such as finance, healthcare, and government. Given the ease of exploitation without authentication or user interaction, attackers can remotely query vulnerable routers to extract data. The lack of known exploits in the wild suggests a window for proactive remediation. However, the widespread adoption of Apollo Federation and GraphQL in European tech ecosystems means the risk is non-trivial, especially for organizations with complex polymorphic GraphQL schemas and inconsistent access control implementations.

To mitigate CVE-2025-64173, European organizations should immediately upgrade Apollo Router to version 1.61.12 or later, or 2.8.1 or later, where the vulnerability is patched. Beyond patching, organizations must audit their GraphQL schema definitions to ensure consistent application of access control directives (@authenticated, @requiresScopes, @policy) across interface types and all their implementing object types. This includes reviewing polymorphic types to confirm that access controls are not solely applied at the interface level but also correctly enforced on each implementation. Implement automated schema validation tools to detect inconsistent directive usage. Additionally, employ runtime monitoring and logging of GraphQL queries to detect anomalous access patterns that may indicate exploitation attempts. Network-level protections such as Web Application Firewalls (WAFs) can be tuned to detect and block suspicious GraphQL queries. Finally, conduct security awareness training for developers on secure GraphQL schema design and access control best practices to prevent similar issues in future deployments.