CVE-2026-91537 in Solaris
Summary
by MITRE • 10/21/2026
Vulnerability in the Oracle Solaris product of Oracle Systems (component: Utility). The supported version that is affected is 11.4. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where Oracle Solaris executes to compromise Oracle Solaris. Successful attacks of this vulnerability can result in takeover of Oracle Solaris. CVSS 3.1 Base Score 7.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
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Analysis
by VulDB Data Team • 10/21/2026
The identified vulnerability resides within the Utility component of Oracle Solaris version 11.4, representing a significant security risk for organizations relying on this operating system environment. This flaw is characterized by its susceptibility to exploitation by attackers who possess low-level privileges and have established local logon access to the infrastructure hosting the affected software. The nature of this vulnerability allows such an attacker to escalate their privileges effectively, leading to a complete compromise of the underlying Oracle Solaris instance. With a CVSS 3.1 base score of 7.8, classified as High severity, the issue impacts all three pillars of the security triad: confidentiality, integrity, and availability. The specific vector indicates that while the attack requires local access and low privileges, it does not require user interaction or complex conditions to execute successfully, making it a critical concern for systems where any unprivileged account exists.
From a technical perspective, this vulnerability aligns with common patterns of privilege escalation flaws often found in system utilities that handle sensitive operations without adequate input validation or permission checks. The ability to take over the entire operating system suggests that the flaw likely involves improper handling of security contexts, potentially allowing an attacker to bypass existing access controls and execute code with root-level privileges. This type of defect is frequently categorized under CWE-269, which addresses Improper Privilege Management, as it allows a user to gain higher levels of authority than intended by the system administrators. The local attack vector (AV:L) combined with low complexity (AC:L) and no required user interaction (UI:N) underscores that once an attacker gains any foothold on the machine, whether through a compromised service account or physical access, they can rapidly escalate to full control.
The operational impact of this vulnerability is severe, as successful exploitation results in total system takeover. An adversary with root-level access can exfiltrate sensitive data, modify critical system files, install persistent backdoors, and use the compromised host as a pivot point for further attacks against other networked systems. This directly compromises confidentiality through unauthorized data access, integrity via potential modification of configurations or binaries, and availability by allowing the attacker to disrupt services or destroy data. The broad impact scope (S:U) indicates that the vulnerability affects resources outside the vulnerable component itself, potentially impacting adjacent processes and system stability.
To mitigate this risk, immediate patching is essential. Organizations running Oracle Solaris 11.4 should apply the latest security patches provided by Oracle to address this specific flaw in the Utility component. In addition to applying updates, administrators should enforce strict least-privilege principles across all user accounts on affected systems. This includes auditing existing accounts for unnecessary elevated privileges and ensuring that local logon capabilities are restricted to only those users who absolutely require it. Implementing robust monitoring solutions can also help detect anomalous privilege escalation attempts or unusual process executions that may indicate exploitation activity. Furthermore, network segmentation strategies should be reviewed to limit the blast radius in case a host is compromised, ensuring that lateral movement from an affected Solaris system does not easily lead to broader infrastructure compromise. Regular vulnerability assessments and penetration testing focused on local privilege escalation vectors are recommended to identify similar weaknesses before they can be exploited by malicious actors.