Executive brief
Capgo, a platform for managing app updates and deployments, contains a security flaw where restricted API 'subkeys' do not actually limit access as intended. An attacker with a valid account can bypass restrictions meant to confine their access to specific organizations or applications, effectively gaining the full permissions of their master account key. This could allow unauthorized users or third-party integrations to view or modify data they were supposed to be restricted from accessing.
Technical details
An authorization bypass exists in the middlewareKey function within hono_middleware.ts. While the system accepts subkeys via the x-limited-key-id header, it fails to overwrite the 'apikey' context used by downstream route handlers, causing them to default to the unrestricted parent key. Additionally, the middleware lacks a validateSubkeyUser check, which could potentially allow users to reference subkey IDs belonging to other accounts. This allows an authenticated attacker to ignore 'limited_to_orgs' and 'limited_to_apps' constraints, granting full access to all resources associated with the parent API key. The issue is resolved in version 12.128.2.
Affected products
- Capgo Capgo < 12.128.2
Timeline
- 2026-05-07: advisory: GitHub Security Advisory published
- 2026-06-24: disclosed: CVE published to NVD