9Router is an AI‑router and token‑saver service. Before the v0.5.6 release, its POST /api/oauth/kiro/api‑key endpoint constructed an upstream URL from a user‑supplied region field. An attacker with valid credentials could supply a crafted region value—such as kiro‑canary.local:8443#—which caused 9Router to send the validation request to the attacker‑controlled host. Because the request forwarded the supplied Kiro API key in the Authorization header, the flaw permitted authenticated server‑side request forgery (CWE‑918) and improper input validation (CWE‑20). The attacker thereby received a privileged credential that could be used to authenticate against the internal Kiro service from a remote location.

The product is 9Router from decolua. All releases before version 0.5.6 are affected; the issue is fixed in 0.5.6. No other vendors or product variants are listed.

The CVSS score of 6.4 classifies the vulnerability as moderate, while the EPSS score of less than 1% indicates a low likelihood of exploitation at present. The flaw is not yet catalogued in CISA’s KEV. Because an attacker must be authenticated to 9Router to trigger the SSRF, the risk is contingent on compromised credentials, but if the attacker can reach the internal network, the forwarded API key could provide access to the Kiro service and enable further lateral movement.