Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks

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No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

13 Oct 2026 16:26:47 UTC

Source modified

14 Oct 2026 15:29:55 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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.

Source published

Oct 13, 2026, 4:26:47 PM (timezone not stated)

Source modified

Oct 14, 2026, 3:29:55 PM (timezone not stated)

Observed here

7 Nov 2026 14:29:56 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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.

Source published

13 Oct 2026 17:17:46 UTC

Source modified

16 Oct 2026 16:00:33 UTC

Observed here

25 Oct 2026 16:19:04 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

### Impact Argo CD checks an Application's AppProject before it creates resources during a sync. That check covers destination namespaces and servers, cluster-scoped resource allow and deny lists, and namespaced resource allow and deny lists, including resource names. PreDelete and PostDelete hooks skip it. When the Application is deleted, Argo CD creates those hooks with the application-controller's credentials on the destination cluster. All versions from v2.10.0 onward are affected, including every currently supported release. v2.9.22 and earlier are not. PostDelete hooks were introduced in [dcc17f70bf](https://github.com/argoproj/argo-cd/commit/dcc17f70bf7db973fe480b8b613189b2c5ac4b4b) (2023-12-18, [#16595](https://github.com/argoproj/argo-cd/pull/16595)) and first released in v2.10.0. That creation path has never applied the project check. PreDelete hooks, added in [3bf3d8a212](https://github.com/argoproj/argo-cd/commit/3bf3d8a2124e772ac651f3fd42375c4e9b8008af) (2025-12-05, [#22288](https://github.com/argoproj/argo-cd/pull/22288)) and first released in v3.3.0, use the same path. v3.2.12 and earlier do not have PreDelete hooks. PreSync, Sync, PostSync, and SyncFail hooks still go through the project check. A user who can push to the Git repository an Application syncs from can commit a hook whose namespace, group, kind, or name the AppProject would refuse on sync. The controller adds the delete finalizer when it sees the hook, and the Application stays Synced until someone deletes it. Deleting the Application creates the hook. What that can reach is bounded by the application-controller's access to the destination cluster. In a typical install that access is broad, so a tenant can create a cluster-scoped object such as a `ClusterRoleBinding`, or an object in a namespace the project does not allow. A hook with no deletion policy is removed after it succeeds. A deletion policy that does not remove the hook on success leaves the object in the cluster. A hook such as a Job can create further objects that Argo CD does not clean up. ### Patches A patch for this vulnerability has been released in the following Argo CD versions: * v3.6.0-rc2 * v3.5.4 * v3.4.10 * v3.3.15 The fix applies the same AppProject destination and resource checks used on sync before creating a PreDelete or PostDelete hook. Argo CD 2.x and 3.0 through 3.2 are out of support and will not receive a patch. Upgrade to a patched 3.3 or newer release. ### Workarounds There is no configuration setting that applies the project check to delete hooks while those hooks stay in use. * Do not grant untrusted users write access to Git repositories that back Applications in restrictive AppProjects. * Limit who can delete Applications. Deletion is what runs PreDelete and PostDelete hooks. * Tighten the application-controller's Kubernetes access so a hook cannot reach sensitive namespaces or APIs. ### Credits The Argo CD team would like to thank @RealFakeAccount, @AdamKorcz, @0xshylines, @thevilledev, @HenriWilliams, @cherez0ff, @ARSB1, and @zwindler for responsibly disclosing this issue according to our [security reporting guidelines](https://github.com/argoproj/argo-cd/blob/master/SECURITY.md#reporting-a-vulnerability). ### References * PostDelete introducing commit: [dcc17f70bf7db973fe480b8b613189b2c5ac4b4b](https://github.com/argoproj/argo-cd/commit/dcc17f70bf7db973fe480b8b613189b2c5ac4b4b) ([#16595](https://github.com/argoproj/argo-cd/pull/16595)), first released in v2.10.0 * PreDelete introducing commit: [3bf3d8a2124e772ac651f3fd42375c4e9b8008af](https://github.com/argoproj/argo-cd/commit/3bf3d8a2124e772ac651f3fd42375c4e9b8008af) ([#22288](https://github.com/argoproj/argo-cd/pull/22288)), first released in v3.3.0 * [AppProject specification](https://argo-cd.readthedocs.io/en/stable/user-guide/projects/) * [Resource hooks](https://argo-cd.readthedocs.io/en/stable/user-guide/resource_hooks/) ### For more information * Open an issue in [the Argo CD issue tracker](https://github.com/argoproj/argo-cd/issues) or [discussions](https://github.com/argoproj/argo-cd/discussions) * Join us on [Slack](https://argoproj.github.io/community/join-slack) in channel #argo-cd

Source published

15 Oct 2026 20:19:31 UTC

Source modified

20 Oct 2026 11:25:50 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Publisher rating · CRITICAL

Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks in github.com/argoproj/argo-cd

Source published

19 Oct 2026 21:08:35 UTC

Source modified

20 Oct 2026 11:25:50 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.