Cases2 cases

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1. IL-0058 Argo CD deleted namespaces shared by several applications, leaving about 97 applications stuck Missing and OutOfSync

   Argo CD users2026

   Symptoms

   After a rolling restart of the Argo CD application-controller, namespaces that several applications shared went into the Terminating state. About 97 applications were then stuck in a Missing/OutOfSync deadlock.

   Resources deleted

   Trigger

   A manual bulk sync with force: true from the Argo CD UI, run during the window after an application-controller restart, on an application whose manifests declared a namespace whose app.kubernetes.io/instance label pointed to a different application.

   Root cause

   Software defect

   Component

   Argo CD

   Contributing factor

   No safeguard on destructive changeUnverified assumptionHarmful manual action

   Action items

   • Refile the problem as #29739: a manual force sync hard-replaces shared cluster-scoped resources through a tracking-ID conflict, ignoring Prune=false

   Lessons

   The sync option Prune=false only protects the prune path; it does not stop a force sync from deleting and recreating a resource. When two Argo CD applications declare the same namespace or other cluster-scoped resource, force-syncing the application that does not own the tracking label can delete it at any time.

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2. IL-0065 Any pod could take over the cluster by rewriting Argo CD's unauthenticated Redis cache (CVE-2024-31989)

   Cycode2024

   Symptoms

   This is a vulnerability report, not an outage, so nothing failed visibly. What an engineer can check is whether the Argo CD Redis server accepts connections without a password from a pod in another namespace, on port 6379 at the address kube-dns returns. In the default installation it did.

   Unauthorised access or a foreign workload

   Trigger

   Cycode Labs installed Argo CD with the default configuration on a new Amazon EKS cluster and connected to its Redis server from a low-privilege pod in another namespace, simulating a compromised pod.

   Root cause

   Software defect

   Component

   Argo CD

   Contributing factor

   Unreviewed defaultsExcessive blast radiusCredential in configuration

   Detection

   Found by Cycode Labs security research, not by an operator.

   Remediation

   • Argo CD released 2.11.1, 2.10.10, 2.9.15 and 2.8.19 with an initialized password for the Redis server

   Lessons

   The hash that checks the cached manifests is computed without a secret key, so anyone who can write to Redis can recompute it and make Argo CD deploy an altered manifest. Cycode recommends upgrading to the fixed versions, checking that the argocd-redis-network-policy NetworkPolicy exists and that a CNI enforces it, using controller-based secret management instead of injecting secrets through Argo CD plugins so secrets never reach Redis, and running Argo CD on a dedicated cluster.

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