# CVE-2026-42880: ArgoCD ServerSideDiff is vulnerable to Kubernetes Secret Extraction

> Attackers with read-only access can extract plaintext Kubernetes Secrets via the ServerSideDiff endpoint due to missing authorization and data masking.

- **Severity:** Critical 9.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 May 2026
- **Updated:** 7 Sep 2026
- **Also known as:** CLEANSTART-2026-MB60182, CLEANSTART-2026-QR94523, MINI-2953-4rgg-pg7p, MINI-5cx5-wrrx-gmm2, MINI-5rpx-vxj7-9mw4, MINI-5wj2-2gx9-6ghj, MINI-7vwh-fq97-g2xm, MINI-8ch6-qxg8-ch36, MINI-8x9w-rc4c-jhwr, MINI-9gfw-gw7f-37c9, MINI-9pqv-p6pw-r96j, MINI-c7mv-r2mp-9m4f, MINI-hr4m-jxw3-pc6j, MINI-jjh2-jmmw-q3wx, MINI-rfv5-v65f-w2gh, MINI-wgg5-wv65-5wgc

## What is CVE-2026-42880?

CVE-2026-42880 is a critical missing authorization vulnerability in Argoproj Argo Cd, published on 7 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. From versions 3.2.0 to before 3.2.11 and 3.3.0 to before 3.3.9, there is a missing authorization and data-masking gap in Argo CD's ServerSideDiff endpoint that allows an attacker with read-only access to extract plaintext Kubernetes Secret data from etcd via the Kubernetes API server's Server-Side Apply dry-run mechanism. This issue has been patched in versions 3.2.11 and 3.3.9.

Weakness: CWE-201 (Insertion of Sensitive Information Into Sent Data), CWE-212 (Improper Removal of Sensitive Information Before Storage or Transfer), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-42880?

It affects 1 product.


Products: Argoproj Argo Cd.

## How do I fix CVE-2026-42880?

Upgrade to a fixed version.

## Is CVE-2026-42880 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42880 exists.

Public exploit code:

- https://github.com/HAERIN-L/POC_CVE-2026-42880 (github_poc): https://github.com/HAERIN-L/POC_CVE-2026-42880

## Other vulnerabilities in Argoproj Argo Cd

- [CVE-2025-55190](https://insights.sbomify.com/CVE-2025-55190/): Argo CD: Project API Token Exposes Repository Credentials (critical 10.0)
- [CVE-2022-29165](https://insights.sbomify.com/CVE-2022-29165/): Argo CD will blindly trust JWT claims if anonymous access is enabled (critical 10.0)
- [CVE-2023-40029](https://insights.sbomify.com/CVE-2023-40029/): Cluster secret might leak in cluster details page in Argo CD (critical 9.9)
- [CVE-2022-24768](https://insights.sbomify.com/CVE-2022-24768/): Improper access control allows admin privilege escalation in Argo CD (critical 9.9)
- [CVE-2024-21652](https://insights.sbomify.com/CVE-2024-21652/): Argo CD vulnerable to Bypassing of Brute Force Protection via Application Crash and In-Memory Data Loss (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42880 and fix it if it is affected.

What it is: CVE-2026-42880 is a critical missing authorization vulnerability in Argoproj Argo Cd, published on 7 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42880 exists.

Affected product: Argoproj Argo Cd. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-42880/ (Markdown: https://insights.sbomify.com/CVE-2026-42880/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42880
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42880
- OSV: https://osv.dev/vulnerability/CVE-2026-42880

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42880/
Summaries are generated and may contain mistakes; the official description above is the record.