Security researchers have disclosed a critical pre-authentication RCE chain in CyberPanel that could let attackers gain a shell on vulnerable hosting servers without valid credentials.

The attack combines weaknesses in the platform’s AI Scanner functionality with stored cross-site scripting and abuse of cron jobs. The issue affects CyberPanel versions earlier than 2.4.4.

CyberPanel is a web hosting control panel for managing websites, DNS, email, databases, and server services. Because it serves as a central control plane, a successful compromise can grant attackers broad access to hosted environments.

Pentera researchers identified the chain during an analysis of internet-facing hosting panels. The researchers found that CyberPanel contained an unauthenticated AI Scanner endpoint intended to receive scan data from an external service.

CyberPanel Pre-Auth RCE Enables Server Shell

The endpoint accepted user-controlled scan results and stored them in the application database without properly sanitizing the content.
This created a stored cross-site scripting vulnerability tracked as CVE-2026-41472.

An attacker could place malicious JavaScript in a forged scan result, but initially faced an important limitation: the request required a valid scan_id. Without a legitimate scan identifier, the application rejected the submitted result.

cronCommand is explicitly excluded from security filtering due to its special characters ( source : pentera ) — `cronCommand` is explicitly excluded from security filtering due to its special characters ( source: Pentera )

The missing piece was an exposed debug API endpoint, /api/ai-scanner/list-api-keys. The endpoint could be accessed without authentication and returned information about recent AI scans, including valid scan IDs..

This access-control issue, tracked as CVE-2026-41473, allowed attackers to obtain the identifier needed to submit a malicious scan result.

After obtaining a valid scan ID, an attacker could inject JavaScript into the stored scan record. The malicious code would not execute immediately.

Instead, it would wait until a CyberPanel administrator opened the AI Scanner results page. When the administrator viewed the poisoned result, the script would run in the administrator’s authenticated browser session.

The RCE chain (Source : pentera) — The RCE chain (Source: Pentera)

The attack code could then use the administrator’s active session and CSRF token to perform actions on the administrator’s behalf.

Pentera researchers demonstrated that the script could silently create a new administrative account. This gave the attacker valid access to the CyberPanel dashboard without needing to steal a password directly.

The final stage involved CyberPanel’s cron job management feature. After logging in with the newly created account, the attacker could create a website and associated system user, then abuse cron job functionality to execute a command on the server.

Researchers found that the cronCommand parameter could dangerously allow shell command execution. This enabled the attacker to obtain a server shell.

Nuclei template to check access to sensitive APIs (Source : pentera) — Nuclei template to check access to sensitive APIs (Source: Pentera)

The chain demonstrates how several individually limited weaknesses can combine to become a full server takeover. The exposed API endpoint leaked data, stored XSS-enabled privilege abuse, and cron job handling enabled command execution.

Pentera reported the vulnerabilities to CyberPanel on May 4, 2026. The CyberPanel team reportedly issued fixes within about four hours, including removal of debug endpoints, authentication for callback functionality, and output escaping.

Administrators should update CyberPanel to the latest patched release immediately. Organizations unable to patch should turn off the AI Scanner feature and restrict access to /api/ai-scanner/list-api-keys and /api/ai-scanner/test-auth until updates can be deployed.

Prevent incidents due to slow investigations. Power your Tier 1 with threat intelligence from 15K SOCs: Integrate TI Lookup in your SOC

The post CyberPanel Pre-Auth RCE Chain Lets Attackers Gain Server Shell via AI Scanner Flaws appeared first on Cyber Security News.