Executive brief
ShellHub, a centralized SSH management platform for remote Linux devices, contains a security flaw that allows users to view sensitive information belonging to other organizations. By using an API key, an attacker can bypass security checks to access a list of a victim's members, their email addresses, and internal system settings. This could lead to unauthorized data exposure and provide a foundation for targeted phishing attacks against the affected organization.
Technical details
A cross-tenant Insecure Direct Object Reference (IDOR) exists in the `GET /api/namespaces/:tenant` endpoint of ShellHub. The vulnerability is caused by a logic error in `api/routes/nsadm.go` where the membership check is conditionally skipped if the `X-ID` header is absent. While standard JWT authentication includes this header, API Key authentication does not, allowing any user with a valid API key to query the details of any other tenant's namespace by its UUID. An attacker can exploit this to retrieve full namespace objects, including member lists (emails, user IDs, roles), device counts, and internal settings. The issue is patched in version 0.24.2.
Affected products
- ShellHub ShellHub <= 0.24.1
Timeline
- 2026-05-01: disclosed: Vulnerability reported to vendor
- 2026-05-07: advisory: GitHub Advisory published
- 2026-05-13: advisory: NVD published CVE-2026-44426