CVE-2026-71965 in CyberPanel
Summary
by MITRE • 08/10/2026
CyberPanel 2.4.3, fixed in commit eca0c3c, contains an authenticated remote code execution vulnerability in the remote backup feature that allows authenticated attackers to gain root-level SSH access by supplying a malicious remote server address. Attackers can exploit the unverified SSH public key retrieval process to write an attacker-controlled public key directly to /root/.ssh/authorized_keys, granting persistent root access to the host system.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/11/2026
The vulnerability in CyberPanel 2.4.3 represents a critical authenticated remote code execution flaw that undermines the security posture of web hosting environments. This issue resides within the remote backup functionality, which is designed to allow administrators to store website data on external servers for disaster recovery purposes. The weakness stems from insufficient input validation and sanitization during the SSH public key retrieval process, creating an avenue for privilege escalation attacks that can compromise entire server infrastructures.
The technical implementation of this vulnerability exploits a fundamental flaw in how CyberPanel handles remote backup configurations. When administrators configure remote backups, the system attempts to retrieve SSH public keys from remote servers to establish secure connections. However, the application fails to properly validate or sanitize the source of these keys, allowing attackers who have already gained authentication access to manipulate the key retrieval process. The vulnerability specifically targets the insecure handling of SSH key management where attacker-controlled public keys can be written directly to the root user's authorized_keys file located at /root/.ssh/authorized_keys.
This flaw enables persistent root-level access through a carefully crafted attack vector that leverages the existing authenticated session. Once an attacker successfully authenticates to the CyberPanel interface, they can manipulate the backup configuration to point to a malicious server controlled by the attacker. The system then retrieves and installs the attacker's public key into the root account's SSH authorized_keys file, effectively bypassing all other authentication mechanisms and establishing a backdoor that persists across system reboots and service restarts.
The operational impact of this vulnerability extends beyond immediate privilege escalation to encompass complete system compromise and potential data exfiltration. Attackers can leverage the root access to modify system configurations, install persistent malware, monitor network traffic, and access all stored website data including sensitive customer information. The vulnerability's authentication requirement means that attackers must first obtain valid credentials through phishing, credential stuffing, or other initial compromise techniques before exploiting this specific flaw. This makes the attack chain more complex but also more dangerous since it provides a reliable method for maintaining persistent access once initial compromise occurs.
Organizations using CyberPanel 2.4.3 should implement immediate mitigations including upgrading to versions that contain the fix from commit eca0c3c, which addresses the unverified SSH public key retrieval process through proper input validation and sanitization. Network segmentation and firewall rules should be implemented to restrict access to the CyberPanel interface to trusted IP ranges only, while multi-factor authentication should be enabled for all administrative accounts. Regular security audits of backup configurations and monitoring for unauthorized changes to SSH key files can help detect exploitation attempts. The vulnerability aligns with CWE-20, which covers improper input validation, and maps to ATT&CK technique T1543.004 for creating or modifying system level execution mechanisms through SSH key manipulation.
Additional defensive measures include implementing strict access controls on the /root/.ssh/authorized_keys file, regular monitoring of SSH login attempts, and deployment of intrusion detection systems that can identify suspicious backup configuration changes. Security teams should also conduct comprehensive penetration testing to verify that no other similar vulnerabilities exist within the application's codebase, particularly in areas involving remote server communications and key management processes. The fix implemented in commit eca0c3c likely includes proper validation of SSH key sources, implementation of certificate pinning mechanisms, and enhanced sanitization of user-supplied backup server addresses to prevent arbitrary file write operations that could be exploited for privilege escalation.