CVE-2026-59801

What is known

9Router through version 0.4.41 contains an unauthenticated access vulnerability that allows remote attackers to interact with provider management API endpoints by sending requests without any credentials due to missing authentication middleware in the Next.js API routes under src/app/api/providers/*. Attackers can enumerate, create, modify, or delete provider connections to expose partial credentials, OAuth tokens, and API keys, redirect AI traffic to attacker-controlled servers, or cause complete denial of service by deleting all provider connections.

Business impact

Successful exploitation of CVE-2026-59801, a critical vulnerability (CVSS 9.3) affecting the affected product, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether the affected product is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
• Reference
• Reference