What’s Vulnerable › Vulnerabilities
CVE-2026-77459: Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks
- Severity: critical (CVSS 9.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-10-13 · updated 2026-10-16
- Weakness: CWE-863
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.
Affected products
- argoproj argo-cd: from 2.10.0, <= 2.14.21; from 3.0.0, < 3.3.15; from 3.4.0, < 3.4.10; from 3.5.0, < 3.5.4; from 3.6.0-rc1, < 3.6.0-rc2
References
- https://github.com/argoproj/argo-cd/commit/1149cdc6e932208c4402183cc3d7b7485239940c
- https://github.com/argoproj/argo-cd/commit/4bc8085b0a6d2296b849539d3d09fc7be7a4a511
- https://github.com/argoproj/argo-cd/commit/7f0a05834b05103d69d7c150e1ee36541b314696
- https://github.com/argoproj/argo-cd/commit/d5dd7019ee65be8895133fe4df554e28074242c4
- https://github.com/argoproj/argo-cd/releases/tag/v3.3.15
- https://github.com/argoproj/argo-cd/releases/tag/v3.4.10
- https://github.com/argoproj/argo-cd/releases/tag/v3.5.4
- https://github.com/argoproj/argo-cd/releases/tag/v3.6.0-rc2
- https://github.com/argoproj/argo-cd/security/advisories/GHSA-fmxq-cgp8-87wp
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