Kubernetes
CVE-2021-25735
MEDIUM
Severity by source
AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
Lifecycle Timeline
1DescriptionNVD
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.
AnalysisAI
A security issue was discovered in kube-apiserver that could allow node updates to bypass a Validating Admission Webhook. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity.
Technical ContextAI
This vulnerability is classified under CWE-372. 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. Affected products include: Kubernetes.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
More in Kubernetes
View allA critical vulnerability in Kubernetes ingress-nginx controller allows unauthenticated attackers with pod network access
Credential-harvesting malware compromised 84 versions of 42 TanStack npm packages on 2026-05-11 via chained GitHub Actio
Kubernetes ingress-nginx contains a configuration injection vulnerability via the mirror-target and mirror-host Ingress
A security issue was discovered in ingress-nginx https://github.com/kubernetes/ingress-nginx where the `auth-url` Ingres
A security issue was discovered in ingress-nginx https://github.com/kubernetes/ingress-nginx where the `auth-tls-match-c
Kubernetes API server in all versions allow an attacker who is able to create a ClusterIP service and set the spec.exter
Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Rated critical severity (CVSS 9.9), this vulne
The Kubernetes integration in GitLab Enterprise Edition 11.x before 11.2.8, 11.3.x before 11.3.9, and 11.4.x before 11.4
Kyverno Kubernetes policy engine prior to 1.x has a privilege escalation vulnerability (CVSS 9.9) allowing policy bypass
Kamaji is the Hosted Control Plane Manager for Kubernetes. Rated critical severity (CVSS 9.9), this vulnerability is rem
Jumpserver is a popular open source bastion host, and Koko is a Jumpserver component that is the Go version of coco, ref
String filter bypass in Inspektor Gadget Kubernetes eBPF tooling before fix. Insufficient string escaping enables filter
Same weakness CWE-372 – Incomplete Internal State Distinction
View allSame technique Authentication Bypass
View allShare
External POC / Exploit Code
Leaving vuln.today