CVE-2026-77459
Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks
- State
- Published
- Severity
- 9.9 Critical
- Published
- Oct 13, 2026
- Updated
- Oct 14, 2026
- Reserved
- Aug 20, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.9 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | GitHub_M |
Weaknesses
- CWE-863 Incorrect Authorization
Affected Products
| Product | Versions |
|---|---|
argo-cdargoproj |
|
References
- https://github.com/argoproj/argo-cd/security/advisories/GHSA-fmxq-cgp8-87wp
- 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
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