Description
An NTLM coercion vulnerability exists on Windows nodes when the subPath supplied in a pod's volumeMounts is set to a symbolic link that points to an attacker-controlled network share. When a kubelet resolves symlinks, it does not reject a target that resolves to a UNC path. As a result, the kubelet will transparently attempt to authenticate to the share using NTLM. This allows an attacker to obtain the NetNTLMv2 hash of the account under which the kubelet is running. An attacker could then attempt to crack the hash to retrieve the corresponding password or relay it to impersonate the node, if the node is domain-joined.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Kubernetes | Kubernetes | v1.34.0 – ≤ v1.34.11, v1.35.0 – ≤ v1.35.8, v1.36.0 – ≤ v1.36.4, v1.37.0 – ≤ v1.37.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kubernetes | No fix yet | — |
Advisories 1
- WID-SEC-2026-3544 Kubernetes (kubelet, kube-controller-manager): Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 3, 2026