Argo CD: Kubernetes Secret Extraction via ArgoCD ServerSideDiff via sensitive annotations

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Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. From 3.2.0 until 3.2.12, 3.3.10, and 3.4.2, Argo CD ServerSideDiff can expose Kubernetes Secret values embedded in the kubectl.kubernetes.io/last-applied-configuration annotation because HideSecretData(target, live, ...) does not fully sanitize ResourceDiff.TargetState and LiveState predicted live Secret objects, allowing sensitive data, stringData, and annotations to appear in UI or CLI diffs. This issue is fixed in versions 3.2.12, 3.3.10, and 3.4.2.

Source published

15 Jul 2026 20:00:46 UTC

Source modified

16 Jul 2026 19:14:44 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 6.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. From 3.2.0 until 3.2.12, 3.3.10, and 3.4.2, Argo CD ServerSideDiff can expose Kubernetes Secret values embedded in the kubectl.kubernetes.io/last-applied-configuration annotation because HideSecretData(target, live, ...) does not fully sanitize ResourceDiff.TargetState and LiveState predicted live Secret objects, allowing sensitive data, stringData, and annotations to appear in UI or CLI diffs. This issue is fixed in versions 3.2.12, 3.3.10, and 3.4.2.

Source published

15 Jul 2026 20:17:04 UTC

Source modified

24 Oct 2026 21:10:00 UTC

Observed here

25 Oct 2026 12:17:14 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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

CVSS 3.1 · [email protected] · Primary · 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

### Summary The original fix for [GHSA-3v3m-wc6v-x4x3](https://github.com/argoproj/argo-cd/security/advisories/GHSA-3v3m-wc6v-x4x3) is incomplete. argocd app diff --server-side-diff can still expose Kubernetes Secret values embedded in the kubectl.kubernetes.io/last-applied-configuration annotation. The prior fix masks top-level Secret data in ServerSideDiff responses, but it does not fully sanitize Secret data stored inside the last-applied-configuration annotation. If a Secret was previously created or updated using client-side apply, that annotation may contain raw data, stringData, and sensitive annotations. These values can be shown in UI/CLI diffs. ### Details The ServerSideDiff endpoint returns ResourceDiff.TargetState / LiveState based on server-side dry-run output. Kubernetes server-side dry-run can return a full predicted live Secret object that carries forward existing live annotations, including: kubectl.kubernetes.io/last-applied-configuration For Secrets created with client-side apply, that annotation can contain a JSON-serialized Secret manifest with sensitive values. The masking path calls HideSecretData(target, live, ...). However, HideSecretData only rewrites the last-applied annotation on the second argument (live). In server-side diff, the first argument can be predictedLive, not a clean Git target. predictedLive can also contain kubectl.kubernetes.io/last-applied-configuration, so the first object’s embedded annotation can remain unmasked. ### PoC Create an app containing this Secret manifest: ```yaml apiVersion: v1 kind: Namespace metadata: name: last-applied-secret-repro --- apiVersion: v1 kind: Secret metadata: name: secret namespace: last-applied-secret-repro annotations: app: test token: SECRETVAL type: Opaque data: password: U0VDUkVUVkFM username: U0VDUkVUVkFM ``` Create and Sync Argo App ```yaml apiVersion: argoproj.io/v1alpha1 kind: Application metadata: name: last-applied-secret-repro namespace: argocd annotations: argocd.argoproj.io/compare-options: ServerSideDiff=true,IncludeMutationWebhook=true spec: project: default destination: server: https://kubernetes.default.svc namespace: last-applied-secret-repro source: repoURL: https://github.com/YOUR_ORG/YOUR_REPO.git targetRevision: HEAD path: last-applied-secret-repro syncPolicy: automated: prune: true selfHeal: true syncOptions: - CreateNamespace=true - ServerSideApply=true ``` Run argo cd app diff `argocd app diff last-applied-secret-repro --server-side-diff --exit-code=false` ``` ❯ argocd app diff last-applied-secret-repro --server-side-diff --exit-code=false ===== /Secret last-applied-secret-repro/secret ====== 10c10,11 < kubectl.kubernetes.io/last-applied-configuration: '{"apiVersion":"v1","data":{"password":"++++++++","username":"++++++++"},"kind":"Secret","metadata":{"annotations":{"app":"test","argocd.argoproj.io/tracking-id":"last-applied-secret-repro:/Secret:last-applied-secret-repro/secret","token":"SECRETVAL"},"name":"secret","namespace":"last-applied-secret-repro"},"type":"Opaque"}' --- > kubectl.kubernetes.io/last-applied-configuration: | > {"apiVersion":"v1","data":{"password":"U0VDUkVUVkFM","username":"U0VDUkVUVkFM"},"kind":"Secret","metadata":{"annotations":{"app":"test","argocd.argoproj.io/tracking-id":"last-applied-secret-repro:/Secret:last-applied-secret-repro/secret","token":"SECRETVAL"},"name":"secret","namespace":"last-applied-secret-repro"},"type":"Opaque"} ``` The secret value can be seen inside the diff ### Impact Authenticated Argo CD users who can view application diffs may be able to read Secret values that should be masked. Impacted values include: Secret data embedded in kubectl.kubernetes.io/last-applied-configuration

Source published

19 May 2026 15:54:21 UTC

Source modified

10 Sep 2026 03:50:47 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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 · 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:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Publisher rating · MODERATE

Argo CD: Kubernetes Secret Extraction via ArgoCD ServerSideDiff via sensitive annotations in github.com/argoproj/argo-cd

Source published

25 Jun 2026 22:34:34 UTC

Source modified

20 Jul 2026 21:26:20 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.