CVE-2026-44949: Unauthenticated namespace creation and RBAC injection via rancher-webhook FleetWorkspace mutating webhook
A Rancher FleetWorkspace admission path allowed side effects to occur in the Rancher webhook handler for versions 0.7.0 up to 0.7.10, 0.8.0 up to 0.8.7, 0.9.0 up to 0.9.6 and 0.10.0 up to 0.10.7. An unauthenticated attacker with network access to the in-cluster rancher-webhook service could submit a crafted admission payload and cause workspace-related Kubernetes objects to be created with attacker-chosen identity data.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
rancher FleetWorkspace (rancher-webhook)to a version that resolves this vulnerability.Fixed in 0.7.0 up to 0.7.10, 0.8.0 up to 0.8.7, 0.9.0 up to 0.9.6 and 0.10.0 up to 0.10.7Patch rancher-webhook FleetWorkspace mutating webhook - Compensating control
Restrict network access to the in-cluster rancher-webhook FleetWorkspace service (rancher-webhook admission path) so unauthenticated attackers cannot reach it and submit crafted admission payloads.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-44949?
CVE-2026-44949 has a risk rating of 75, indicating a high severity level.
How do I fix CVE-2026-44949?
To fix CVE-2026-44949, update Rancher FleetWorkspace to version 0.7.11, 0.8.8, 0.9.7, or 0.10.8 or later.
What vulnerability does CVE-2026-44949 exploit?
CVE-2026-44949 exploits an unauthenticated namespace creation and RBAC injection via the Rancher webhook.
Which versions of Rancher FleetWorkspace are affected by CVE-2026-44949?
CVE-2026-44949 affects Rancher FleetWorkspace versions 0.7.0 to 0.7.10, 0.8.0 to 0.8.7, 0.9.0 to 0.9.6, and 0.10.0 to 0.10.7.
Who can exploit CVE-2026-44949?
An unauthenticated attacker with network access to the in-cluster rancher-webhook service can exploit CVE-2026-44949.