CVE-2026-21935 is a vulnerability in Oracle Solaris 11's driver component that allows a high privileged attacker with existing logon access to the Solaris infrastructure to compromise the system. The attack requires human interaction from a user other than the attacker, which could involve social engineering or tricking a legitimate user into performing an action that facilitates exploitation. The vulnerability enables unauthorized creation, deletion, or modification of critical data or all data accessible by Oracle Solaris, thus impacting confidentiality and integrity. The CVSS 3.1 vector (AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N) indicates the attack is local, requires low complexity, high privileges, and user interaction, with no impact on availability. Although no known exploits are reported in the wild, the vulnerability is considered easily exploitable under the stated conditions. This vulnerability could be leveraged to manipulate or exfiltrate sensitive data, disrupt data integrity, or escalate privileges further within the Solaris environment. Given Solaris's use in enterprise and critical infrastructure environments, the vulnerability represents a significant risk if not mitigated promptly.

For European organizations, the impact of CVE-2026-21935 can be substantial, especially for those relying on Oracle Solaris 11 in critical sectors such as finance, telecommunications, energy, and government. Unauthorized modification or deletion of critical data can lead to operational disruptions, data breaches, and compliance violations under regulations like GDPR. The confidentiality breach could expose sensitive personal or corporate data, while integrity compromises may affect decision-making, financial transactions, or system stability. Although availability is not directly impacted, the downstream effects of data corruption or loss could cause service interruptions. The requirement for high privileges and user interaction limits the attack surface but does not eliminate risk, particularly in environments with privileged users who may be targeted via social engineering. European organizations with complex Solaris deployments must consider this vulnerability a moderate risk that requires timely remediation to prevent potential exploitation and data compromise.

1. Apply Oracle's official patches or updates for Solaris 11 as soon as they become available to address this vulnerability. 2. Restrict and monitor high privileged user accounts rigorously, employing the principle of least privilege to minimize unnecessary access. 3. Implement strong user awareness and training programs to reduce the risk of successful social engineering or inadvertent user interaction that could facilitate exploitation. 4. Deploy enhanced logging and monitoring solutions to detect unusual activities involving privileged accounts and user interactions within the Solaris environment. 5. Use multi-factor authentication (MFA) for all privileged access to reduce the likelihood of credential misuse. 6. Conduct regular audits of access controls and user permissions to ensure compliance with security policies. 7. Segment Solaris infrastructure to limit lateral movement in case of compromise. 8. Employ endpoint protection and intrusion detection systems tailored for Solaris to identify potential exploitation attempts early.