{"cve":"CVE-2021-25735","nvd":{"published":"2021-09-06T12:15:07.617","modified":"2026-06-17T03:42:22.503","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H","score":6.5},"cwes":["CWE-372"],"references":["https://github.com/kubernetes/kubernetes/issues/100096","https://groups.google.com/g/kubernetes-security-announce/c/FKAGqT4jx9Y","https://github.com/kubernetes/kubernetes/issues/100096","https://groups.google.com/g/kubernetes-security-announce/c/FKAGqT4jx9Y"],"products":["kubernetes:kubernetes"],"source":"nvd","synced_at":"2026-10-19T21:21:57.125947417+00:00"},"epss":{"cve":"CVE-2021-25735","score":0.05375,"percentile":0.9266,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-g42g-737j-qx6j","url":"https://osv.dev/vulnerability/GHSA-g42g-737j-qx6j","summary":"Access Restriction Bypass in kube-apiserver","modified":"2026-09-10T03:49:26.789295488Z","packages":[{"ecosystem":"Go","name":"k8s.io/kubernetes","purl":"pkg:golang/k8s.io/kubernetes","ranges":[">=1.20.0 <1.20.6"],"fixed":["1.20.6"]},{"ecosystem":"Go","name":"k8s.io/kubernetes","purl":"pkg:golang/k8s.io/kubernetes","ranges":[">=1.19.0 <1.19.10"],"fixed":["1.19.10"]},{"ecosystem":"Go","name":"k8s.io/kubernetes","purl":"pkg:golang/k8s.io/kubernetes","ranges":["<1.18.18"],"fixed":["1.18.18"]}]},{"id":"GO-2022-0907","url":"https://osv.dev/vulnerability/GO-2022-0907","summary":"Access Restriction Bypass in kube-apiserver in k8s.io/kubernetes","modified":"2026-02-04T03:59:40.340851Z","packages":[{"ecosystem":"Go","name":"k8s.io/kubernetes","purl":"pkg:golang/k8s.io/kubernetes","ranges":["<1.18.18",">=1.19.0 <1.19.10",">=1.20.0 <1.20.6"],"fixed":["1.18.18","1.19.10","1.20.6"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}