# CVE-2026-33396: Code injection in oneuptime

> Low-privileged users can execute arbitrary commands on the Probe host by bypassing the Playwright sandbox in OneUptime Synthetic Monitors.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **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:** 26 Mar 2026
- **Updated:** 26 Mar 2026
- **Also known as:** GHSA-cqpg-phpp-9jjg

## What is CVE-2026-33396?

CVE-2026-33396 is a critical code injection vulnerability in oneuptime, published on 26 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.35, a low-privileged authenticated user (ProjectMember) can achieve remote command execution on the Probe container/host by abusing Synthetic Monitor Playwright script execution. Synthetic monitor code is executed in VMRunner.runCodeInNodeVM with a live Playwright page object in context. The sandbox relies on a denylist of blocked properties/methods, but it is incomplete. Specifically, _browserType and launchServer are not blocked, so attacker code can traverse `page.context().browser()._browserType.launchServer(...)` and spawn arbitrary processes. Version 10.0.35 contains a patch.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-693 (Protection Mechanism Failure), CWE-184 (Incomplete List of Disallowed Inputs)

## Which versions are affected by CVE-2026-33396?

It affects 1 product.


Products: Hackerbay Oneuptime.

## How do I fix CVE-2026-33396?

No fix has been published for CVE-2026-33396 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33396 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33396 exists.

## Other vulnerabilities in oneuptime

- [CVE-2026-32306](https://insights.sbomify.com/CVE-2026-32306/): OneUptime ClickHouse SQL Injection via Aggregate Query Parameters (critical 10.0)
- [CVE-2026-30956](https://insights.sbomify.com/CVE-2026-30956/): OneUptime has authorization bypass via client‑controlled is-multi-tenant-query header (critical 10.0)
- [CVE-2026-30957](https://insights.sbomify.com/CVE-2026-30957/): OneUptime Synthetic Monitor RCE via exposed Playwright browser object (critical 10.0)
- [CVE-2026-30887](https://insights.sbomify.com/CVE-2026-30887/): OneUptime Affected by Unsandboxed Code Execution in Probe Allows Any Project Member to Achieve RCE (critical 10.0)
- [CVE-2026-30921](https://insights.sbomify.com/CVE-2026-30921/): OneUptime Synthetic Monitor RCE via exposed Playwright browser object (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33396 and fix it if it is affected.

What it is: CVE-2026-33396 is a critical code injection vulnerability in oneuptime, published on 26 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-2026-33396 exists.

Affected product: oneuptime. 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-2026-33396/ (Markdown: https://insights.sbomify.com/CVE-2026-33396/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33396
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33396
- OSV: https://osv.dev/vulnerability/CVE-2026-33396

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33396/
Summaries are generated and may contain mistakes; the official description above is the record.