An authenticated remote attacker can achieve full system compromise on Greenbone OS by leveraging a malicious vulnerability test to trigger a stack buffer overflow.

This vulnerability is an out-of-bounds write (CWE-787) occurring within the NASL processing engine. An attacker with low-level user privileges can supply a specially crafted vulnerability test script to overflow the stack and gain full control over the underlying system.

The potential for total system compromise presents a severe risk to organizational security, as Greenbone systems typically reside in sensitive positions with network-wide visibility. With a CVSS score of 8.8, the vulnerability carries a high severity rating that could lead to the unauthorized exfiltration of internal network data, lateral movement, or complete loss of administrative control over security scanning infrastructure.

Immediate Action: Review the official Greenbone security advisory at https://www.greenbone.net/.well-known/csaf/white/2026/gbsa2026-03.json to identify available patches or mitigation scripts for your specific version.

Proactive Monitoring: Monitor system logs for unusual execution patterns within the NASL scanner process and investigate any unexpected crashes or memory access violations.

Compensating Controls: Restrict access to the scanner management interface to trusted administrative users only, and implement network segmentation to isolate the scanning appliance from untrusted network segments.

Public Exploit Available: Unknown

Given the high CVSS score and the potential for total system compromise, organizations should treat this vulnerability with high urgency. Administrators must verify their current version of Greenbone OS or openvas-scanner and apply the necessary patches as soon as they are provided by the vendor to prevent unauthorized system access.