# CVE-2026-31836: Mass Assignment Privilege Escalation in Checkmate

> Authenticated users can escalate privileges to superadmin via mass assignment in the profile update endpoint, gaining full administrative access.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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:** No
- **Published:** 20 Mar 2026
- **Updated:** 20 Mar 2026
- **Also known as:** GHSA-6368-x7wr-wpm2

## What is CVE-2026-31836?

CVE-2026-31836 is a high-severity vulnerability in bluewave-labs Checkmate, published on 20 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Checkmate is an open-source, self-hosted tool designed to track and monitor server hardware, uptime, response times, and incidents in real-time with beautiful visualizations. In versions from 3.5.1 and prior, a mass assignment vulnerability in Checkmate's user profile update endpoint allows any authenticated user to escalate their privileges to superadmin, bypassing all role-based access controls. An attacker can modify their user role to gain complete administrative access to the application, including the ability to view all users, modify critical configurations, and access sensitive system data. At time of publication, there are no publicly available patches.

Weakness: CWE-285 (Improper Authorization), CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2026-31836?

It affects 1 product.


Products: Bluewavelabs Checkmate.

## How do I fix CVE-2026-31836?

No fix has been published for CVE-2026-31836 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-31836 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31836 exists.

## Other vulnerabilities in bluewave-labs Checkmate

- [CVE-2026-30829](https://insights.sbomify.com/CVE-2026-30829/): Checkmate: Unauthenticated Access to Unpublished Status Page (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31836 and fix it if it is affected.

What it is: CVE-2026-31836 is a high-severity vulnerability in bluewave-labs Checkmate, published on 20 Mar 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-2026-31836 exists.

Affected product: bluewave-labs Checkmate. 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-2026-31836/ (Markdown: https://insights.sbomify.com/CVE-2026-31836/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31836
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31836
- OSV: https://osv.dev/vulnerability/CVE-2026-31836

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31836/
Summaries are generated and may contain mistakes; the official description above is the record.