{"id":"CVE-2026-77459","published":"2026-10-13T17:17:46.050","lastModified":"2026-10-16T16:00:33.533","description":"Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. From 2.10.0 until 3.3.15, 3.4.10, 3.5.4, and 3.6.0-rc2, Argo CD creates PostDelete resource hooks without applying the AppProject destination and resource authorization checks used during ordinary synchronization. The omitted checks include cluster-scoped and namespaced resource allow/deny lists. A user who can write to an Application's Git repository can commit a delete hook targeting a forbidden namespace, server, group, kind, or resource name, and deletion of the Application causes the application-controller to create that resource with its destination-cluster credentials. The reachable impact is bounded by the controller's cluster access but can include cluster-scoped resources, disallowed namespaces, persistent hook objects, and secondary objects created by a hook Job. PreSync, Sync, PostSync, and SyncFail hooks continue to use the normal project checks. This issue is fixed in versions 3.3.15, 3.4.10, 3.5.4, and 3.6.0-rc2.","cvssScore":9.9,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cwes":["CWE-863"],"vendors":[],"products":[],"references":[{"url":"https://github.com/argoproj/argo-cd/commit/1149cdc6e932208c4402183cc3d7b7485239940c","tags":[]},{"url":"https://github.com/argoproj/argo-cd/commit/4bc8085b0a6d2296b849539d3d09fc7be7a4a511","tags":[]},{"url":"https://github.com/argoproj/argo-cd/commit/7f0a05834b05103d69d7c150e1ee36541b314696","tags":[]},{"url":"https://github.com/argoproj/argo-cd/commit/d5dd7019ee65be8895133fe4df554e28074242c4","tags":[]},{"url":"https://github.com/argoproj/argo-cd/releases/tag/v3.3.15","tags":[]},{"url":"https://github.com/argoproj/argo-cd/releases/tag/v3.4.10","tags":[]},{"url":"https://github.com/argoproj/argo-cd/releases/tag/v3.5.4","tags":[]},{"url":"https://github.com/argoproj/argo-cd/releases/tag/v3.6.0-rc2","tags":[]},{"url":"https://github.com/argoproj/argo-cd/security/advisories/GHSA-fmxq-cgp8-87wp","tags":[]}],"exploitRefs":[{"url":"https://github.com/argoproj/argo-cd/commit/1149cdc6e932208c4402183cc3d7b7485239940c","tags":[]},{"url":"https://github.com/argoproj/argo-cd/commit/4bc8085b0a6d2296b849539d3d09fc7be7a4a511","tags":[]},{"url":"https://github.com/argoproj/argo-cd/commit/7f0a05834b05103d69d7c150e1ee36541b314696","tags":[]},{"url":"https://github.com/argoproj/argo-cd/commit/d5dd7019ee65be8895133fe4df554e28074242c4","tags":[]},{"url":"https://github.com/argoproj/argo-cd/releases/tag/v3.3.15","tags":[]},{"url":"https://github.com/argoproj/argo-cd/releases/tag/v3.4.10","tags":[]},{"url":"https://github.com/argoproj/argo-cd/releases/tag/v3.5.4","tags":[]},{"url":"https://github.com/argoproj/argo-cd/releases/tag/v3.6.0-rc2","tags":[]},{"url":"https://github.com/argoproj/argo-cd/security/advisories/GHSA-fmxq-cgp8-87wp","tags":[]}],"hasPoc":true,"ai":{"summary":"Argo CD allows users with write access to Application Git repositories to create PostDelete hooks that bypass normal authorization checks, potentially enabling deletion of forbidden cluster-scoped resources or objects in disallowed namespaces. This creates a privilege escalation vector where attackers can delete critical system resources through crafted hook definitions.","exploitability":"Exploitation requires a user with write access to an Application's Git repository, which is typically less privileged than cluster admin, making it moderately easy to achieve initial compromise before leveraging this vulnerability.","blast_radius":"The impact could include deletion of cluster-scoped resources like CRDs, namespaces, or persistent objects, potentially affecting multiple applications and the overall Kubernetes cluster stability.","remediation":"Upgrade to Argo CD version 3.3.15, 3.4.10, 3.5.4, or 3.6.0-rc2 immediately to remediate this authorization bypass vulnerability.","detection":"Monitor for Application resource changes in the Argo CD controller logs that include PostDelete hook definitions, particularly when these hooks target cluster-scoped resources or namespaces not permitted by the AppProject configuration.","tags":["privilege-escalation","kubernetes","gitops","authorization"],"model":"garnet-coder","analyzedAt":"2026-10-14T08:45:47.065Z"}}