CVE-2026-56678 in 9router
Summary
by MITRE • 07/15/2026
9Router is an AI router & token saver. Prior to 0.5.6, the Kiro API-key validation endpoint POST /api/oauth/kiro/api-key builds an upstream URL using a user-controlled region value, allowing an authenticated attacker to supply a crafted region such as kiro-canary.local:8443# and cause 9Router to send the Kiro validation request to an attacker-controlled host while forwarding the submitted Kiro API key as an Authorization header. This issue is fixed in version 0.5.6.
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Analysis
by VulDB Data Team • 07/15/2026
The vulnerability in 9Router represents a critical server-side request forgery (SSRF) flaw that arises from improper input validation within the Kiro API-key validation endpoint. This weakness exists in the POST /api/oauth/kiro/api-key endpoint where the application constructs an upstream URL using a user-controllable region parameter without adequate sanitization or validation. The vulnerability stems from CWE-918, which specifically addresses server-side request forgery conditions where applications fail to properly validate and sanitize user-supplied URLs or hostnames before making outbound requests.
The technical implementation of this flaw allows authenticated attackers to manipulate the region parameter to construct malicious URLs that bypass normal network restrictions. When an attacker supplies a crafted region value such as kiro-canary.local:8443#, the application processes this input without proper validation, causing it to establish connections to attacker-controlled hosts while maintaining the legitimate Kiro API key in the Authorization header. This configuration creates a scenario where sensitive authentication credentials can be exfiltrated or used for unauthorized access to external systems.
The operational impact of this vulnerability is significant as it enables attackers to perform reconnaissance and potentially gain access to internal services that would normally be protected by network segmentation. The flaw allows for arbitrary outbound connections from the 9Router system, potentially exposing internal infrastructure and sensitive data to external threat actors. Attackers can leverage this vulnerability to probe internal networks, harvest additional credentials, or establish persistence mechanisms within the target environment.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK technique T1071.004 for application layer protocol usage and T1566 for credential access through social engineering attacks that exploit misconfigured applications. The vulnerability demonstrates poor input validation practices and highlights the importance of implementing strict URL parsing and validation mechanisms. Organizations should implement network segmentation controls and monitor outbound connections from critical systems to detect potential exploitation attempts. The fix in version 0.5.6 likely involves implementing proper URL validation, sanitization, and restricting outbound connections to predefined trusted domains only.
This vulnerability serves as a reminder of the critical importance of validating all user inputs, particularly when constructing URLs for outbound requests. The flaw exemplifies how seemingly minor input validation gaps can result in significant security implications, especially in systems handling authentication tokens and sensitive credentials. Organizations should conduct regular security assessments of API endpoints to identify similar SSRF vulnerabilities and implement proper access controls and monitoring mechanisms to detect unauthorized outbound connections from their systems.