ShellHub has cross-tenant IDOR in GET /api/namespaces/:tenant via API Key bypasses membership check

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-44426: 0.31% estimated exploitation activity in the next 30 days; percentile 23.65 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary GET /api/namespaces/:tenant returns the full namespace object — including the members list (user IDs, e-mails, roles), settings, and device counts — to any caller authenticated by an API Key, for any tenant, regardless of the API Key's own tenant scope. The handler conditionally skips the membership check when the user ID (X-ID) is absent, which is exactly the case for API Key authentication. Affected versions ShellHub Community v0.24.1 (validated). Root cause api/routes/nsadm.go:75-102 — membership check is skipped when c.ID() is nil: AuthRequest (api/routes/auth.go:53-64) sets only X-Tenant-ID, X-Role, and X-API-KEY for API Key authentication — never X-ID. So c.Request().Header.Get("X-ID") returns "", c.ID() returns nil, and the membership check is bypassed. Proof of concept (validated live against v0.24.1) Impact - Enumeration of any ShellHub namespace by tenant UUID. - Disclosure of member e-mails, user IDs, and roles → user enumeration and targeted phishing against the…

Published by the source

7 May 2026, 03:02 UTC

Last modified by the source

14 May 2026, 20:43 UTC

Source last checked

26 Oct 2026, 15:22 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vwx9-7qcf-gg7f

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# Patch Next advisory brief: CVE-2026-44426

Advisory: ShellHub has cross-tenant IDOR in `GET /api/namespaces/:tenant` via API Key bypasses membership check
IDs: CVE-2026-44426, GHSA-vwx9-7qcf-gg7f
Record: https://patchnext.com/advisories/cve-2026-44426 (revision 1, source checked 26 Oct 2026, 15:22 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/shellhub-io/shellhub 0.24.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/shellhub-io/shellhub: affected <= 0.24.1; fixed in 0.24.2

## Suggested inspection (read-only)
- Go github.com/shellhub-io/shellhub: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/shellhub-io/shellhub.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-vwx9-7qcf-gg7f (GitHub-reviewed advisory GHSA-vwx9-7qcf-gg7f lists affected ranges: Go github.com/shellhub-io/shellhub >=0 <=0.24.1)

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