{"cve":"CVE-2021-41254","nvd":{"published":"2021-11-12T18:15:07.600","modified":"2026-06-17T04:08:11.080","status":"Modified","description":"kustomize-controller is a Kubernetes operator, specialized in running continuous delivery pipelines for infrastructure and workloads defined with Kubernetes manifests and assembled with Kustomize. Users that can create Kubernetes Secrets, Service Accounts and Flux Kustomization objects, could execute commands inside the kustomize-controller container by embedding a shell script in a Kubernetes Secret. This can be used to run `kubectl` commands under the Service Account of kustomize-controller, thus allowing an authenticated Kubernetes user to gain cluster admin privileges. In affected versions multitenant environments where non-admin users have permissions to create Flux Kustomization objects are affected by this issue. This vulnerability was fixed in kustomize-controller v0.15.0 (included in flux2 v0.18.0) released on 2021-10-08. Starting with v0.15, the kustomize-controller no longer executes shell commands on the container OS and the `kubectl` binary has been removed from the container image. To prevent the creation of Kubernetes Service Accounts with `secrets` in namespaces owned by tenants, a Kubernetes validation webhook such as Gatekeeper OPA or Kyverno can be used.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-78"],"references":["https://github.com/fluxcd/kustomize-controller/security/advisories/GHSA-35rf-v2jv-gfg7","https://github.com/fluxcd/kustomize-controller/security/advisories/GHSA-35rf-v2jv-gfg7"],"products":["fluxcd:kustomize-controller"],"source":"nvd","synced_at":"2026-10-19T21:24:39.218183596+00:00"},"epss":{"cve":"CVE-2021-41254","score":0.01824,"percentile":0.78804,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-35rf-v2jv-gfg7","url":"https://osv.dev/vulnerability/GHSA-35rf-v2jv-gfg7","summary":"Privilege escalation to cluster admin on multi-tenant environments","modified":"2026-09-10T03:49:09.466080790Z","packages":[{"ecosystem":"Go","name":"github.com/fluxcd/kustomize-controller","purl":"pkg:golang/github.com/fluxcd/kustomize-controller","ranges":["<0.15.0"],"fixed":["0.15.0"]}]},{"id":"GO-2022-0260","url":"https://osv.dev/vulnerability/GO-2022-0260","summary":"Privilege escalation to cluster admin on multi-tenant environments in github.com/fluxcd/kustomize-controller","modified":"2026-02-04T02:38:30.562568Z","packages":[{"ecosystem":"Go","name":"github.com/fluxcd/kustomize-controller","purl":"pkg:golang/github.com/fluxcd/kustomize-controller","ranges":["<0.15.0"],"fixed":["0.15.0"]}]}],"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."]}