CVE-2026-3415 in API Control Plane
Summary
by MITRE • 08/07/2026
The XML and schema validation functionalities within the SchemaValidator Mediator process XML input as part of validation flows. Under certain conditions, the XML parser allows the resolution of external entities when handling user-supplied XML content during validation operations. This behavior can occur when an attacker supplies crafted XML payloads to the relevant mediator flows with sufficient privileges.
Successful exploitation may allow a highly privileged actor to read files accessible within the server hosting the affected product. Additionally, it may be possible to trigger outbound requests to unintended internal or external locations, depending on the server environment and network configuration. Specially crafted XML payloads can also lead to excessive resource consumption during parsing, impacting the availability of the product.
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Analysis
by VulDB Data Team • 08/07/2026
The vulnerability described represents a critical security flaw in the SchemaValidator Mediator component that processes XML input during validation operations. This issue stems from inadequate handling of external entity resolution within the XML parser implementation, creating an attack surface where malicious actors can manipulate the validation flow through crafted XML payloads. The vulnerability specifically manifests when the system processes user-supplied XML content with sufficient privileges to permit external entity resolution, potentially allowing unauthorized access to sensitive server resources.
The technical exploitation of this vulnerability follows a pattern consistent with classic xml external entity injection attacks, where the XML parser's default behavior permits resolution of external references during document parsing. This flaw directly maps to CWE-611 Information Exposure Through Improperly Constructed XML Entities and aligns with ATT&CK technique T1059.007 for execution through XML files. When an attacker crafts malicious XML content that includes external entity declarations, the parser resolves these references against the server's network configuration, potentially accessing local files, internal services, or triggering outbound communications to attacker-controlled endpoints.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass multiple attack vectors including lateral movement and resource exhaustion. A highly privileged actor who successfully exploits this vulnerability can read arbitrary files from the server filesystem, potentially accessing sensitive configuration files, credential stores, or application data that should remain protected. The outbound request capability enables attackers to establish command and control channels or exfiltrate data through internal network connections, while the resource consumption aspect creates availability risks through denial of service conditions during parsing operations. This multi-faceted impact makes the vulnerability particularly dangerous in enterprise environments where the mediator component likely handles critical validation workflows for multiple applications.
Mitigation strategies should focus on implementing proper XML parser configuration that disables external entity resolution and DTD processing entirely. Organizations must configure the SchemaValidator Mediator to enforce strict XML parsing policies that prevent any external resource access during validation operations. The implementation of input validation controls, including XML schema restrictions and proper sanitization of user-supplied content, provides additional defense layers. Network segmentation and firewall rules can help limit potential outbound communications from vulnerable systems. Regular security assessments should verify that the parser configuration prevents entity resolution and that the system properly handles malformed XML payloads without consuming excessive computational resources. The remediation approach should align with industry standards such as OWASP Top Ten and NIST guidelines for secure coding practices in XML processing components, ensuring comprehensive protection against similar vulnerabilities in other system components.
This vulnerability demonstrates the critical importance of proper XML parser security configuration and highlights how seemingly routine validation operations can become attack vectors when external entity resolution is not properly controlled. The combination of information disclosure, remote code execution potential through resource exhaustion, and network communication capabilities makes this a particularly dangerous flaw that requires immediate attention from security teams responsible for protecting enterprise infrastructure.