CVE-2026-91378 in Siebel CRM Integration
Summary
by MITRE • 10/21/2026
Vulnerability in the Siebel CRM Integration product of Oracle Siebel CRM (component: Open Integration). Supported versions that are affected are 25.12-26.9. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Siebel CRM Integration. Successful attacks require human interaction from a person other than the attacker and while the vulnerability is in Siebel CRM Integration, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Siebel CRM Integration accessible data as well as unauthorized read access to a subset of Siebel CRM Integration accessible data. CVSS 3.1 Base Score 6.1 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).
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Analysis
by VulDB Data Team • 10/21/2026
The identified vulnerability resides within the Open Integration component of Oracle Siebel CRM, specifically affecting supported versions ranging from 25.12 through 26.9. This security flaw is classified as an easily exploitable issue that permits unauthenticated attackers to compromise the integrity and confidentiality of the system via network access over HTTP. The core technical nature of this vulnerability aligns with CWE-79, which describes Cross-Site Scripting (XSS) or similar injection flaws where user input is not properly sanitized before being processed by the application logic. In the context of Siebel CRM Integration, this likely manifests as a scenario where maliciously crafted HTTP requests can manipulate server-side behavior or client-side rendering in ways that bypass standard authentication mechanisms due to insufficient validation of incoming data streams.
The operational impact of exploiting this vulnerability is significant because it allows an attacker to perform unauthorized updates, inserts, and deletes against accessible data within the Siebel CRM Integration layer. Furthermore, successful exploitation grants unauthorized read access to a subset of sensitive information stored or processed by the integration module. This dual impact on both confidentiality and integrity means that attackers can not only exfiltrate critical business data but also alter records, potentially leading to data corruption, financial loss, or regulatory non-compliance depending on the nature of the affected CRM data. The CVSS 3.1 base score of 6.1 reflects a medium severity level, driven by low attack complexity and no required privileges for the attacker, though it is tempered slightly by the requirement for human interaction.
A critical aspect of this vulnerability is its potential to cause scope changes in broader organizational security postures. While the technical flaw exists within Siebel CRM Integration, successful attacks can significantly impact additional products connected through the integration framework. This lateral movement capability means that compromising one component can serve as a foothold for attacking other systems linked via APIs or data synchronization processes. From an ATT&CK perspective, this vulnerability facilitates techniques associated with Initial Access and Collection, particularly those involving web-based applications where user interaction is leveraged to bypass security controls. The requirement for human interaction suggests the use of social engineering tactics, such as phishing links that trigger malicious HTTP requests when clicked by a victim, thereby aligning with ATT&CK technique T1566.002 (Spearphishing Link).
Mitigation strategies must address both immediate remediation and long-term architectural resilience. Oracle has likely released patches for the affected versions 25.12 through 26.9; therefore, applying these updates is the primary defense mechanism to eliminate the underlying code flaw responsible for improper input validation. In addition to patching, organizations should implement strict access controls on HTTP endpoints exposed by Siebel CRM Integration, ensuring that only authorized IP ranges or authenticated sessions can interact with sensitive integration points. Web Application Firewalls (WAFs) configured with rulesets targeting injection and XSS patterns can provide an additional layer of defense by inspecting incoming traffic for malicious payloads before they reach the application server.
Furthermore, security teams should enforce Content Security Policy headers to mitigate potential client-side impacts if any script execution is possible through this vulnerability. Regular audits of integration points are essential to identify other systems that may be susceptible to similar scope-expansion attacks. Monitoring logs for unusual HTTP request patterns or unexpected data modifications can aid in early detection of exploitation attempts. Given the reliance on human interaction for successful exploitation, user awareness training regarding phishing and suspicious links remains a vital complementary control to reduce the attack surface effectively.