CVE-2026-116811 in OpenPanel
Summary
by MITRE • 10/27/2026
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.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability identified in OpenPanel versions prior to 3.0.0 represents a critical sandbox escape within its JavaScript runtime environment, specifically targeting the Abstract Syntax Tree (AST) validator mechanism designed to enforce security boundaries for project members. This flaw stems from an insufficient validation of how function constructors are handled during code execution, allowing attackers with write access privileges to circumvent the intended allowlist restrictions. The core technical issue lies in the ability to alias or reference the Function constructor through indirect means, such as accessing payload.constructor.constructor, which effectively bypasses the static analysis checks that normally prevent arbitrary code execution within the isolated worker process context.
From a technical perspective, this vulnerability exploits the dynamic nature of JavaScript's prototype chain and object construction mechanisms. By resolving the constructor property recursively on an injected or manipulated payload object, an attacker can obtain a reference to the global Function constructor without directly invoking it in a way that triggers immediate detection by the AST validator. Once this reference is secured locally within the execution scope, it can be invoked with arbitrary string arguments containing malicious JavaScript code. This process effectively elevates privileges from a restricted sandboxed environment to full control over the worker process, as the newly created function executes with the same permissions and context as other legitimate runtime operations, thereby breaking out of the intended isolation boundaries.
The operational impact of this vulnerability is severe, particularly in multi-tenant or collaborative environments where multiple users have write access to shared projects. An attacker can execute arbitrary commands on the server hosting the OpenPanel instance, potentially leading to complete system compromise, data exfiltration, lateral movement within the network, and disruption of services for other tenants sharing the same infrastructure. This aligns with CWE-78 Improper Neutralization of Special Elements used in an OS Command (OS Command Injection) when considering the broader implications of arbitrary code execution, as well as CWE-94 Improper Control of Generation of Code (Code Injection). Furthermore, this attack vector is consistent with MITRE ATT&CK technique T1059.007 JavaScript, which describes adversaries using JavaScript to execute malicious payloads within browser or runtime environments that may have broader system access depending on the context and permissions granted to the executing process.
Mitigation strategies must prioritize immediate patching of OpenPanel to version 3.0.0 or later, where these validation logic flaws are addressed by strengthening the AST allowlist enforcement and restricting direct access to sensitive constructors like Function through more rigorous sanitization checks. In addition to software updates, organizations should implement strict least-privilege principles for project members, ensuring that write access does not inherently grant capabilities that could be leveraged for sandbox escapes. Web Application Firewalls (WAFs) can provide a temporary layer of defense by detecting and blocking patterns associated with constructor aliasing or unusual JavaScript execution flows, although this is not a substitute for fixing the underlying code vulnerability. Regular security audits focusing on runtime validation logic and continuous monitoring for anomalous process behavior in worker environments are also recommended to detect potential exploitation attempts early.