CVE-2026-56221: Cap-go SQL Injection in cloudflare.ts (CVSS 6.5)

Technical summary

The vulnerability stems from unsafe string interpolation in the cloudflare.ts module within Cap-go. SQL queries are constructed by directly concatenating user-supplied input from API request bodies without parameterized query techniques or input sanitization. An authenticated attacker with read-level API key credentials can craft payloads in multiple parameters (deviceIds, search, version_name, cursor, actions) to inject arbitrary SQL clauses. This allows conditional logic manipulation to retrieve data from tables normally restricted by authorization checks. The flaw affects analytics data access control but does not enable data modification or denial of service.

Business impact

For organizations running Cap-go to manage mobile application deployments and analytics, this vulnerability enables unauthorized cross-tenant or cross-project data disclosure. A malicious insider with read API credentials—or an attacker who compromises such credentials—can exfiltrate competitive analytics, usage patterns, and customer data belonging to other deployments. This creates regulatory risk under GDPR, CCPA, and similar frameworks, and erodes customer trust if data exposure occurs. Organizations must audit historical API access logs to determine whether the exposure window resulted in actual breaches.

Affected systems

Cap-go versions before 12.128.2 are affected. The vulnerability requires an attacker to first possess a valid authenticated API key with read-level permissions, limiting the attack surface to internal users, service accounts, or compromised credentials. No information on whether Cap-go SaaS instances are auto-patched or require manual deployment updates is provided; organizations should verify their deployment model (self-hosted vs. cloud-managed) with Cap-go documentation or support.

Exploitability

Exploitation requires valid authentication, which significantly reduces opportunistic attack likelihood. However, the bar for attack is low once an attacker has legitimate credentials: no complex logic or race conditions are needed, and SQL injection payloads can be tested iteratively. The vulnerability is straightforward to execute programmatically. The fact that the vulnerability remained undetected until version 12.128.2 suggests it was not actively exploited in the wild, but this does not diminish the risk to organizations using older versions.

Remediation

The primary remediation is to upgrade Cap-go to version 12.128.2 or later, which addresses the SQL injection flaw through parameterized query implementation or input validation. As an interim control, organizations should implement least-privilege API key policies: review which users and service accounts hold read-level keys, rotate or revoke unnecessary keys, and enable API key audit logging if available. Network-based controls such as IP whitelisting for API access can reduce the attack surface. After patching, review API audit logs from the vulnerability window to identify any suspicious queries that may have accessed unauthorized data.

Patch guidance

Deploy Cap-go 12.128.2 or later into your environment. If you operate a self-hosted Cap-go instance, check the Cap-go release notes and upgrade documentation for any breaking changes or migration steps. If you use Cap-go cloud services, verify whether patching is automatic or requires manual action. Test the upgrade in a staging environment first to confirm compatibility with your existing API integrations and deployed applications. Once patched, validate that SQL injection payloads are properly rejected or safely escaped.

Detection guidance

Monitor API audit logs for unusual query patterns in the identified vulnerable parameters (deviceIds, search, version_name, cursor, actions). Look for SQL keywords (UNION, SELECT, WHERE, OR) embedded in parameter values. Implement Web Application Firewall (WAF) rules to block common SQL injection patterns in API request bodies targeting Cap-go endpoints. Query database transaction logs for unexpected SELECT operations initiated by service accounts or read-level API keys, particularly queries that appear to access rows outside the expected authorization scope. Retrospective analysis should focus on the time window between the vulnerability's introduction and your patch deployment.

Why prioritize this

Although the CVSS score is 6.5 (medium), this vulnerability should be prioritized based on business context. The flaw enables direct unauthorized data access rather than requiring additional exploitation steps, and it affects data that typically contains customer identities, usage metrics, and competitive intelligence. For SaaS providers or organizations with multi-tenant deployments, cross-tenant data leakage carries significant compliance and contractual implications. However, the authentication requirement limits the risk to insider threats or credential compromise scenarios, which justifies a medium rather than high priority. Organizations with critical analytics data or strict regulatory obligations should treat this as high priority.

Risk score, explained

The CVSS 3.1 score of 6.5 reflects high confidentiality impact (C:H), low attack complexity (AC:L), and a requirement for low privileges (PR:L). The score correctly captures that no network-level authentication barriers exist beyond the API key itself, making the attack simple to execute once credentials are obtained. The score does not account for the low likelihood of opportunistic exploitation due to authentication requirements, nor does it weight business-specific factors such as data sensitivity or regulatory exposure. Organizations should apply their own risk multipliers based on whether they hold regulated data (PCI, HIPAA, GDPR subject data) or operate in industries where competitive data theft carries significant business impact.

Frequently asked questions