Vulnerability-Lookup

GHSA-FMXQ-CGP8-87WP

Vulnerability from github – Published: 2026-10-15 20:19 – Updated: 2026-10-15 20:19

Summary

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

Details

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 (2023-12-18, #16595) and first released in v2.10.0. That creation path has never applied the project check. PreDelete hooks, added in 3bf3d8a212 (2025-12-05, #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.

References

PostDelete introducing commit: dcc17f70bf7db973fe480b8b613189b2c5ac4b4b (#16595), first released in v2.10.0
PreDelete introducing commit: 3bf3d8a2124e772ac651f3fd42375c4e9b8008af (#22288), first released in v3.3.0
AppProject specification
Resource hooks

For more information

Open an issue in the Argo CD issue tracker or discussions
Join us on Slack in channel #argo-cd

Severity

9.9 (Critical)


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

Show details on source website

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/argoproj/argo-cd/v2"
      },
      "ranges": [
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          "events": [
            {
              "introduced": "2.10.0"
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    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/argoproj/argo-cd/v3"
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        "name": "github.com/argoproj/argo-cd/v3"
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          "type": "ECOSYSTEM"
        }
      ]
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  ],
  "aliases": [
    "CVE-2026-77459"
  ],
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    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-15T20:19:31Z",
    "nvd_published_at": "2026-10-13T17:17:46Z",
    "severity": "CRITICAL"
  },
  "details": "### Impact\n\nArgo CD checks an Application\u0027s 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\u0027s credentials on the destination cluster.\n\nAll 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.\n\nA 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\u0027s 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.\n\n### Patches\n\nA patch for this vulnerability has been released in the following Argo CD versions:\n\n* v3.6.0-rc2\n* v3.5.4\n* v3.4.10\n* v3.3.15\n\nThe fix applies the same AppProject destination and resource checks used on sync before creating a PreDelete or PostDelete hook.\n\nArgo 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.\n\n### Workarounds\n\nThere is no configuration setting that applies the project check to delete hooks while those hooks stay in use.\n\n* Do not grant untrusted users write access to Git repositories that back Applications in restrictive AppProjects.\n* Limit who can delete Applications. Deletion is what runs PreDelete and PostDelete hooks.\n* Tighten the application-controller\u0027s Kubernetes access so a hook cannot reach sensitive namespaces or APIs.\n\n### Credits\n\nThe 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).\n\n### References\n\n* 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\n* 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\n* [AppProject specification](https://argo-cd.readthedocs.io/en/stable/user-guide/projects/)\n* [Resource hooks](https://argo-cd.readthedocs.io/en/stable/user-guide/resource_hooks/)\n\n### For more information\n\n* 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)\n* Join us on [Slack](https://argoproj.github.io/community/join-slack) in channel #argo-cd",
  "id": "GHSA-fmxq-cgp8-87wp",
  "modified": "2026-10-15T20:19:31Z",
  "published": "2026-10-15T20:19:31Z",
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    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/security/advisories/GHSA-fmxq-cgp8-87wp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77459"
    },
    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/commit/1149cdc6e932208c4402183cc3d7b7485239940c"
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      "type": "WEB",
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    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/commit/7f0a05834b05103d69d7c150e1ee36541b314696"
    },
    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/commit/d5dd7019ee65be8895133fe4df554e28074242c4"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/argoproj/argo-cd"
    },
    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/releases/tag/v3.3.15"
    },
    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/releases/tag/v3.4.10"
    },
    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/releases/tag/v3.5.4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/releases/tag/v3.6.0-rc2"
    }
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  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks"
}

CVE-2026-77459 (GCVE-0-2026-77459)

Vulnerability from cvelistv5 – Published: 2026-10-13 16:26 – Updated: 2026-10-14 15:29

Title

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

Summary

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.

Severity

9.9 (Critical)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-14 15:27 UTC

CWE

CWE-863 - Incorrect Authorization

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7634 records in the last 180 days details

References

9 references

URL	Tags
https://github.com/argoproj/argo-cd/security/advi…	x_refsource_CONFIRM
https://github.com/argoproj/argo-cd/commit/1149cd…	x_refsource_MISC
https://github.com/argoproj/argo-cd/commit/4bc808…	x_refsource_MISC
https://github.com/argoproj/argo-cd/commit/7f0a05…	x_refsource_MISC
https://github.com/argoproj/argo-cd/commit/d5dd70…	x_refsource_MISC
https://github.com/argoproj/argo-cd/releases/tag/…	x_refsource_MISC
https://github.com/argoproj/argo-cd/releases/tag/…	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/…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
argoproj	argo-cd	Affected: >= 2.10.0, <= 2.14.21 Affected: >= 3.0.0, < 3.3.15 Affected: >= 3.4.0, < 3.4.10 Affected: >= 3.5.0, < 3.5.4 Affected: >= 3.6.0-rc1, < 3.6.0-rc2

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-77459",
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Action not permitted

GHSA-FMXQ-CGP8-87WP

Impact

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Workarounds

Credits

References

For more information

CVE-2026-77459 (GCVE-0-2026-77459)

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