[Security Advisory] CVE-2026-2270: StatefulSet and ControllerRevision write permissions allow cross-namespace pod creation

[Nathan Herz]

Hello Kubernetes Community,

A confused deputy attack exists in the StatefulSet controller that allows a user with namespace-scoped write permissions on StatefulSet and ControllerRevision objects to create a cross-namespace pod. An attacker exploiting this vulnerability would have full control over the resulting pod’s metadata and specification, including namespace selection. Note that the cross-namespace pod will be immediately deleted by the garbage collector unless the attacker is able to construct a valid StatefulSet OwnerReference. This would require referencing the UID of an existing StatefulSet in the victim’s namespace.

This issue has been rated Medium (5.9) CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N, and assigned CVE-2026-2270.

Affected Versions

• kube-controller-manager: <= v1.34.11

• kube-controller-manager: <= v1.35.8

• kube-controller-manager: <= v1.36.4

• kube-controller-manager: = v1.37.0

How do I mitigate this vulnerability?

This issue can be mitigated by upgrading to a fixed kube-controller-manager version. The fixed versions are patched to ensure that only the spec field in StatefulSets will be restored from ControllerRevisions.

Fixed Versions

• kube-controller-manager: >= v1.34.12

• kube-controller-manager: >= v1.35.9

• kube-controller-manager: >= v1.36.5

• kube-controller-manager: >= v1.37.1

If you find evidence that this vulnerability has been exploited, please contact secu...@kubernetes.io.

Additional Details

See the GitHub issue for more details: https://github.com/kubernetes/kubernetes/issues/142097

Acknowledgements

This vulnerability was reported by ImanOracle.

The issue was fixed and coordinated by: 

Maciej Szulik @soltysh

Filip Křepinský @atiratree

Verónica López @Verolop

Jeremy Rickard @jeremyrickard

Nathan Herz @natherz97

Thank you,

Nathan Herz on behalf of the Kubernetes Security Response Committee