CVE-2026-56318: Capgo Organization Enumeration via Information Disclosure

Technical summary

The /private/validate_password_compliance endpoint in Capgo fails to implement consistent error handling across different failure modes. When an unauthenticated attacker submits a request with a malformed organization ID, a non-existent organization ID, or an existing organization ID, the endpoint returns distinguishable HTTP status codes or error message content. This differential response pattern allows an attacker to infer organization existence without authentication. The vulnerability is rooted in CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), where the 'sensitive information' in this case is the mere existence of an organization ID. The endpoint's design fails to normalize responses across failure cases, inadvertently creating a side-channel for enumeration.

Business impact

Organization enumeration can facilitate targeted phishing campaigns, social engineering, competitive intelligence gathering, and reconnaissance prior to more sophisticated attacks. While this vulnerability alone does not grant access to data or systems, it significantly lowers barriers to attack targeting. For Capgo users, the risk is primarily reputational and operational: unauthorized parties can confirm the existence of their organizations on the platform, potentially revealing business relationships or partnerships that should remain confidential. In multi-tenant SaaS environments, tenant enumeration is particularly sensitive because it can expose organizational structure to competitors or threat actors.

Affected systems

Capgo releases prior to version 12.128.2 are affected. The vulnerability is tied to the /private/validate_password_compliance endpoint, meaning any deployment serving this endpoint without the patch is at risk. The endpoint's unauthenticated nature means no special access, keys, or credentials are required to exploit it.

Exploitability

Exploitability is straightforward: the attack requires only network access to the vulnerable endpoint and no authentication. An attacker can write a simple script to iterate through potential UUIDs or use common organization naming patterns to enumerate valid IDs. The low complexity and lack of prerequisites make this vulnerability accessible to relatively unsophisticated threat actors. However, practical impact is limited to reconnaissance; the vulnerability does not grant unauthorized access to customer data, administrative functions, or system integrity.

Remediation

Upgrade Capgo to version 12.128.2 or later. This version implements consistent error handling on the /private/validate_password_compliance endpoint, preventing response differentiation that enables enumeration. Organizations should prioritize patching before the endpoint is exposed to hostile network segments or the internet.

Patch guidance

Apply Capgo version 12.128.2 or any later release. Verify the patch by checking the installed version and confirming that the /private/validate_password_compliance endpoint no longer returns distinguishable error responses for valid versus invalid organization IDs. Consider testing the patch in a staging environment first to ensure compatibility with any local customizations. If you cannot immediately patch, implement network-level access controls to restrict unauthenticated access to the endpoint.

Detection guidance

Monitor logs for repeated requests to the /private/validate_password_compliance endpoint from single IP addresses or for patterns of organization ID enumeration (e.g., sequential or dictionary-based UUID attempts). Look for sudden spikes in requests with 4xx responses to that endpoint, which may indicate active enumeration. If you maintain HTTP access logs, search for requests to /private/validate_password_compliance and correlate request patterns with organization ID parameters. Note that pre-patch detection is difficult because the vulnerability produces 'normal' HTTP responses; focus on behavioral anomalies (high request volume, systematic patterns) rather than signature-based detection.

Why prioritize this

This vulnerability merits prioritization despite its MEDIUM CVSS score because organization enumeration is a critical first step in targeted attacks. In competitive or sensitive verticals (finance, healthcare, government), information disclosure of organizational structure can be weaponized quickly. The ease of exploitation (no authentication, no special tools) and the low barrier to abuse by reconnaissance tools make it a natural escalation point if combined with other vulnerabilities. Patch promptly, but reserve urgent response for deployments in high-risk industries or where organization IDs are particularly sensitive.

Risk score, explained

CVE-2026-56318 scores 5.3 MEDIUM under CVSS v3.1 (vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N). The score reflects low integrity and availability impact (both zero), limited confidentiality impact (only organizational existence is disclosed, not customer data), and the Network/Low-Complexity/No-Auth attack surface. The score appropriately captures that this is a reconnaissance vulnerability rather than a direct data breach or system compromise. Organizations handling sensitive customer data or operating in regulated environments should treat this as higher-priority than the CVSS alone suggests, because enumeration is a necessary precursor to targeted attacks.

Frequently asked questions