A flaw was found in kubernetes. Users authorized to list or watch one type of namespaced custom resource cluster-wide can read custom resources of a different kind in the same API group they are not authorized to read.

Node address isn't always verified when proxying

A security issue was discovered in Kubernetes where users may be able to launch containers that bypass the mountable secrets policy enforced by the ServiceAccount admission plugin when using ephemeral containers. The policy ensures pods running with a service account may only reference secrets specified in the service account’s secrets field. Kubernetes clusters are only affected if the ServiceAccount admission plugin and the kubernetes.io/enforce-mountable-secrets annotation are used together with ephemeral containers.

This issue affects kube-apiserver. Clusters are impacted by this vulnerability if:

1. The ServiceAccount admission plugin is used. Most clusters should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount 2. The kubernetes.io/enforce-mountable-secrets annotation is used by a service account. This annotation is not added by default. 3. Pods using ephemeral containers.

A security issue was discovered in kube-apiserver that could allow node updates to bypass a Validating Admission Webhook. Clusters are only affected by this vulnerability if they run a Validating Admission Webhook for Nodes that denies admission based at least partially on the old state of the Node object. Validating Admission Webhook does not observe some previous fields.

A flaw was found in Kubernetes, where the amount of disk space the /etc/hosts file can use is unconstrained . This flaw can allow attacker-controlled pods to cause a denial of service if they have permission to write to the node's /etc/hosts file.

A server side request forgery (SSRF) flaw was found in Kubernetes. The kube-controller-manager allows authorized users with the ability to create StorageClasses or certain Volume types to leak up to 500 bytes of arbitrary information from the master's host network. This can include secrets from the kube-apiserver through the unauthenticated localhost port (if enabled).

A flaw was found in the Kubernetes API server, where it allows an attacker to escalate their privileges from a compromised node. This flaw allows an attacker who can intercept requests on a compromised node, to redirect those requests, along with their credentials, to perform actions on other endpoints that trust those credentials (including other clusters), allowing for escalation of privileges. The highest threat from this vulnerability is to confidentiality, integrity, and system availability.

Cloud Native Computing Foundation (CNCF) CNI (Container Networking Interface) 0.7.4 has a network firewall misconfiguration which affects Kubernetes. The CNI 'portmap' plugin, used to setup HostPorts for CNI, inserts rules at the front of the iptables nat chains; which take precedence over the KUBE- SERVICES chain. Because of this, the HostPort/portmap rule could match incoming traffic even if there were better fitting, more specific service definition rules like NodePorts later in the chain. The issue is fixed in CNI 0.7.5 and Kubernetes 1.11.9, 1.12.7, 1.13.5, and 1.14.0.

The Kubernetes API server mistakenly allows access to a cluster-scoped custom resource if the request is made as if the resource were namespaced. Authorizations for the resource accessed in this manner are enforced using roles and role bindings within the namespace, meaning that a user with access only to a resource in one namespace could create, view update or delete the cluster-scoped resource (according to their namespace role privileges).

A third issue was discovered with the Kubernetes kubectl cp command that could enable a directory traversal such that a malicious container could replace or create files on a user’s workstation. The vulnerability is a client-side defect and requires user interaction to be exploited.

This vulnerability allows a malicious container to cause a file to be created or replaced on the client computer when the client uses the kubectl cp operation. The vulnerability is a client-side defect and requires user interaction to be exploited.

Upstream Issue:

https://github.com/kubernetes/kubernetes/issues/80984

External References:

https://groups.google.com/forum/#!topic/kubernetes-security-discuss/Vf31dXp0EJc

A flaw was found kubernetes. The parsing of YAML manifests by the Kubernetes API server could lead to a denial-of-service attack leaving it vulnerable to an instance of a "billion laughs" attack. The highest threat from this vulnerability is to system availability.

A security issue was discovered in Kubernetes where a malicious or compromised pod could bypass network restrictions enforced by network policies during namespace deletion. The order in which objects are deleted during namespace termination is not defined, and it is possible for network policies to be deleted before the pods that they protect. This can lead to a brief period in which the pods are running, but network policies that should apply to connections to and from the pods are not enforced.

As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane.

A security issue was discovered in Kubernetes where actors that control the responses of MutatingWebhookConfiguration or ValidatingWebhookConfiguration requests are able to redirect kube-apiserver requests to private networks of the apiserver. If that user can view kube-apiserver logs when the log level is set to 10, they can view the redirected responses and headers in the logs.

A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.

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.

An incorrect authorization vulnerability exists in Esri Portal for ArcGIS 11.4, 11.5 and 12.0 on Windows, Linux and Kubernetes that did not correctly check permissions assigned to developer credentials.

Esri Portal for ArcGIS versions 12.1 and earlier on Windows, Linux and Kubernetes have a missing authentication for critical function vulnerability allows a remote, unauthenticated attacker to access an unprotected API. The following versions are known to be affected: Portal for ArcGIS 12.1 and earlier. Other unsupported versions may also be affected. Esri recommends that users apply the Portal for ArcGIS Security 2026 Update 2 Patch to remediate this vulnerability.

A SQL Injection vulnerability exists in Esri ArcGIS Server versions 11.3, 11.4 and 11.5 on Windows, Linux and Kubernetes. This vulnerability allows a remote, unauthenticated attacker to execute arbitrary SQL commands via a specific ArcGIS Feature Service operation. Successful exploitation can potentially result in unauthorized access, modification, or deletion of data from the underlying Enterprise Geodatabase.

A vulnerability exists in the NodeRestriction admission controller in Kubernetes clusters where node users can delete their corresponding node object by patching themselves with an OwnerReference to a cluster-scoped resource. If the OwnerReference resource does not exist or is subsequently deleted, the given node object will be deleted via garbage collection.

A flaw was found in Kubernetes that allows attackers on adjacent networks to reach services exposed on localhost ports, previously thought to be unreachable. This flaw allows an attacker to gain privileges or access confidential information for any services listening on localhost ports that are not protected by authentication.

The Kubelet component in versions 1.15.0-1.15.9, 1.16.0-1.16.6, and 1.17.0-1.17.2 has been found to be vulnerable to a denial of service attack via the kubelet API, including the unauthenticated HTTP read-only API typically served on port 10255, and the authenticated HTTPS API typically served on port 10250.

A flaw was found in kubernetes. In Kubernetes, if the logging level is to at least 4, processing a malformed docker config file will result in the contents of the docker config file being leaked, which can include pull secrets or other registry credentials. This can occur with client tools like kubectl, or other components that use registry credentials in a docker config file.

A flaw was found in kubernetes. In Kubernetes, if the logging level is to at least 9, authorization and bearer tokens will be written to log files. This can occur both in API server logs and client tool output like kubectl. Previously, CVE-2019-11250 was assigned for the same issue for logging levels of at least 4.

A denial of service vulnerability was found in the kube-apiserver, allowing authorized users sending malicious YAML payloads to cause kube-apiserver to consume excessive CPU cycles while parsing YAML.

Upstream Issue:

https://github.com/kubernetes/kubernetes/issues/89535

kubectl (k8s.io/kubernetes/pkg/kubectl) does not neutralize escape, meta or control sequences contained in the raw data it outputs to a terminal. This includes but is not limited to the unstructured string fields in objects such as Events.

A flaw was found in kubernetes. If a potential attacker can already create or edit services and pods, then they may be able to intercept traffic from other pods (or nodes) in the cluster.

A denial of service vulnerability was found in the Kubernetes API server. This flaw allows a remote attacker to send repeated, crafted HTTP requests to exhaust available memory and cause a crash.

A security issue was discovered in Kubernetes where a user may be able to redirect pod traffic to private networks on a Node. Kubernetes already prevents creation of Endpoint IPs in the localhost or link-local range, but the same validation was not performed on EndpointSlice IPs.

The Kubernetes kube-controller-manager in versions v1.0-v1.17 is vulnerable to a credential leakage via error messages in mount failure logs and events for AzureFile and CephFS volumes.