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

github.com/argoproj/argo-cd/v2 (go), github.com/argoproj/argo-cd/v3 (go)

### 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…

First seen: 15 Oct 2026
Last update: 15 Oct 2026, 20:19 UTC
Fixed in: github.com/argoproj/argo-cd/v3 3.3.15
github.com/argoproj/argo-cd/v3 3.4.10
github.com/argoproj/argo-cd/v3 3.5.4
github.com/argoproj/argo-cd/v3 3.6.0-rc2
Identifiers: CVE-2026-77459
CVSS: 9.9
Source: GitHub advisory
On the menu as: Go
Kubernetes

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks
Severity: critical. Patch status: partial fix.
Affected: github.com/argoproj/argo-cd/v2 (go), github.com/argoproj/argo-cd/v3 (go)
Fixed in: github.com/argoproj/argo-cd/v3 3.3.15, github.com/argoproj/argo-cd/v3 3.4.10, github.com/argoproj/argo-cd/v3 3.5.4, github.com/argoproj/argo-cd/v3 3.6.0-rc2
Ids: CVE-2026-77459

### 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…

## Steps
1. Search every lockfile and manifest (package-lock.json, yarn.lock, pnpm-lock.yaml, requirements*.txt, poetry.lock, uv.lock, composer.lock, go.sum, Cargo.lock, Gemfile.lock) for `github.com/argoproj/argo-cd/v3`. For each hit, compare the installed version with the fix on the same major line: github.com/argoproj/argo-cd/v3 3.3.15, github.com/argoproj/argo-cd/v3 3.4.10, github.com/argoproj/argo-cd/v3 3.5.4, github.com/argoproj/argo-cd/v3 3.6.0-rc2. If it's lower, give the exact upgrade command for the package manager this repo uses.
2. Check Dockerfiles, compose files and Kubernetes or Helm manifests for affected images and tags. Report the tag in use and the first fixed tag.
3. There is only a partial fix. Until one ships: ### 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…

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-77459") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://github.com/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/security/advisories/GHSA-fmxq-cgp8-87wp https://nvd.nist.gov/vuln/detail/CVE-2026-77459
https://pwned.coffee/i/argo-cd-appproject-destination-namespace-and-resource-re-cve-2026-77459

Sources

Totalone very hot coffee