CVE-2026-91426 in Siebel CRM Deployment
Summary
by MITRE • 10/21/2026
Vulnerability in the Siebel CRM Deployment product of Oracle Siebel CRM (component: Server Infrastructure). Supported versions that are affected are 17.0-26.9. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where Siebel CRM Deployment executes to compromise Siebel CRM Deployment. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Siebel CRM Deployment accessible data. CVSS 3.1 Base Score 5.5 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).
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Analysis
by VulDB Data Team • 10/21/2026
The identified vulnerability resides within the Server Infrastructure component of Oracle Siebel CRM Deployment, specifically affecting supported versions ranging from 17.0 through 26.9. This security flaw represents a significant risk to organizations relying on this enterprise customer relationship management platform for managing critical business data and workflows. The core issue stems from an improper access control mechanism within the deployment infrastructure, which fails to adequately restrict resource consumption or validate input parameters during specific administrative operations. While the vulnerability does not allow remote exploitation over a network without prior authentication, it presents a serious threat when an attacker has already gained low-privileged access to the underlying operating system where Siebel CRM Deployment is installed. This scenario typically arises from compromised user accounts, insider threats, or lateral movement following an initial breach of less secure systems within the same infrastructure segment.
From a technical perspective, the flaw enables a low privileged attacker with local logon capabilities to compromise the integrity and confidentiality of the Siebel CRM Deployment environment. The vulnerability is characterized by its ease of exploitation, requiring no user interaction and possessing a relatively high attack complexity score that reflects straightforward trigger conditions once local access is established. By leveraging this weakness, an adversary can bypass intended security boundaries to extract sensitive information stored within the deployment database or configuration files. This could include customer personal identifiable information, financial records, strategic business plans, or internal communication logs. The absence of proper isolation between different privilege levels allows the attacker to escalate their influence over the application layer, effectively turning a low-privilege shell into a gateway for comprehensive data exfiltration.
The operational impact of this vulnerability is predominantly centered on confidentiality breaches rather than integrity violations or availability disruptions. As indicated by the CVSS 3.1 base score of 5.5 and its vector configuration emphasizing high confidentiality impacts, successful exploitation leads to unauthorized access to critical data accessible by Siebel CRM Deployment. This means that while system functionality may remain intact and services continue to operate normally, the secrecy of stored information is completely compromised. For enterprises handling regulated data subject to GDPR, HIPAA, or PCI-DSS compliance requirements, such a breach can trigger severe regulatory penalties, legal liabilities, and substantial reputational damage. Furthermore, the stolen data could serve as intelligence for further social engineering attacks against employees or customers, amplifying the long-term risk beyond the immediate incident scope.
In terms of industry standard classifications, this vulnerability aligns with CWE-269 Improper Privilege Management and potentially CWE-732 Incorrect Permission Assignment for Critical Resource if the root cause involves misconfigured file system permissions. It also maps to MITRE ATT&CK techniques related to Local Account Discovery and Data from Information Repositories, as an attacker would likely enumerate local accounts before exploiting this flaw to access stored data. The attack vector is classified as Local (AV:L), indicating that physical or remote desktop protocol access to the host machine is a prerequisite for exploitation. This distinction underscores the importance of securing not just network-facing services but also internal server infrastructure against insider threats and compromised endpoints.
Mitigation strategies must focus on both immediate remediation and long-term architectural hardening. Oracle has likely released patches addressing this specific flaw in subsequent updates within the 17.x to 26.9 release train, making prompt application of these security fixes the primary defense mechanism. Organizations should verify their current version against supported update levels and apply all relevant cumulative patch sets immediately. Beyond patching, implementing strict least-privilege principles is essential; administrators must ensure that service accounts running Siebel components operate with minimal necessary permissions, avoiding local administrator rights wherever possible. Additionally, deploying endpoint detection and response solutions can help monitor for anomalous processes or unauthorized data access patterns originating from the deployment server. Network segmentation should also be reviewed to limit lateral movement opportunities, ensuring that even if a low-privileged account is compromised on one system, it cannot easily reach critical database servers hosting Siebel CRM data. Regular audits of user accounts and active sessions will further reduce the window of opportunity for attackers leveraging this vulnerability.