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
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kube-controller-manager: <= v1.34.11
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kube-controller-manager: <= v1.35.8
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kube-controller-manager: <= v1.36.4
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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
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kube-controller-manager: >= v1.34.12
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kube-controller-manager: >= v1.35.9
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kube-controller-manager: >= v1.36.5
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kube-controller-manager: >= v1.37.1
If you find evidence that this vulnerability has been exploited, please contact security@kubernetes.io.
Additional Details
See the GitHub issue for more details: CVE-2026-2270: StatefulSet and ControllerRevision write permissions allow cross-namespace pod creation · Issue #142097 · kubernetes/kubernetes · GitHub
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