Vulnerability · Published Oct 13, 2026 · Assigned by GitHub_M
CVE-2026-77459Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks
Critical 9.9
In plain English
A critical-severity incorrect authorization in argo-cd from argoproj. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/argoproj/argo-cd | no fix listed | GO-2026-6784 |
| Go | github.com/argoproj/argo-cd/v2 | no fix listed | GO-2026-6784 |
| Go | github.com/argoproj/argo-cd/v2 | no fix listed | GHSA-fmxq-cgp8-87wp |
| Go | github.com/argoproj/argo-cd/v3 | 3.5.4 | GHSA-fmxq-cgp8-87wp |
| Go | github.com/argoproj/argo-cd/v3 | 3.6.0-rc2 | GHSA-fmxq-cgp8-87wp |
| Go | github.com/argoproj/argo-cd/v3 | 3.3.15, 3.4.10, 3.5.4, 3.6.0-rc2 | GO-2026-6784 |
| Go | github.com/argoproj/argo-cd/v3 | 3.3.15 | GHSA-fmxq-cgp8-87wp |
| Go | github.com/argoproj/argo-cd/v3 | 3.4.10 | GHSA-fmxq-cgp8-87wp |
Affected products (as reported)
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
References
- https://github.com/argoproj/argo-cd/security/advisories/GHSA-fmxq-cgp8-87wp x_refsource_CONFIRM
- https://github.com/argoproj/argo-cd/commit/1149cdc6e932208c4402183cc3d7b7485239940c x_refsource_MISC
- https://github.com/argoproj/argo-cd/commit/4bc8085b0a6d2296b849539d3d09fc7be7a4a511 x_refsource_MISC
- https://github.com/argoproj/argo-cd/commit/7f0a05834b05103d69d7c150e1ee36541b314696 x_refsource_MISC
- https://github.com/argoproj/argo-cd/commit/d5dd7019ee65be8895133fe4df554e28074242c4 x_refsource_MISC
- https://github.com/argoproj/argo-cd/releases/tag/v3.3.15 x_refsource_MISC
- https://github.com/argoproj/argo-cd/releases/tag/v3.4.10 x_refsource_MISC
- https://github.com/argoproj/argo-cd/releases/tag/v3.5.4 x_refsource_MISC
- https://github.com/argoproj/argo-cd/releases/tag/v3.6.0-rc2 x_refsource_MISC