CVE-2026-46840 - Oracle REST Data Services Takeover Vulnerability

CVE-2026-46840 is a highly critical vulnerability affecting Oracle REST Data Services (ORDS), specifically the Backend-as-a-Service component. The vulnerability impacts versions 24.2.0 through 26.1.0. An unauthenticated attacker with network access via HTTPS can exploit this flaw to completely compromise an ORDS instance. Successful exploitation leads to full control of the ORDS instance and may also cause significant impact on other products that rely on the compromised ORDS instance due to the scope change aspect of the vulnerability. This presents a substantial risk to organizations utilizing affected versions of Oracle REST Data Services, potentially allowing attackers to gain unauthorized access to sensitive data, modify system configurations, or disrupt critical services.

Attack Chain

1. Attacker identifies a vulnerable Oracle REST Data Services instance accessible via HTTPS.
2. Attacker sends a specially crafted HTTPS request to the vulnerable Backend-as-a-Service component.
3. The malicious request exploits a flaw within the ORDS application, bypassing authentication checks.
4. The vulnerability allows the attacker to execute arbitrary code within the ORDS instance.
5. Attacker leverages the code execution to escalate privileges within the ORDS environment.
6. Attacker gains complete control over the ORDS instance, achieving full administrative access.
7. The attacker can now access sensitive data, modify configurations, or disrupt the ORDS service.
8. Due to the scope change impact, the attacker pivots to compromise other products or services that rely on the now-compromised ORDS instance, expanding the impact of the attack.

Impact

Successful exploitation of CVE-2026-46840 can result in a complete takeover of Oracle REST Data Services. This can lead to unauthorized access to sensitive data, modification of critical system configurations, and disruption of essential services. The vulnerability’s potential to impact additional products amplifies the risk, potentially exposing a wider range of systems and data to compromise. Given the CVSS base score of 10.0, the impact is considered critical, affecting confidentiality, integrity, and availability.

Recommendation

• Apply the patch provided by Oracle to address CVE-2026-46840 on all affected Oracle REST Data Services instances (versions 24.2.0-26.1.0).
• Deploy the Sigma rule “Detect CVE-2026-46840 Exploitation Attempt via Malicious HTTPS Request” to identify exploitation attempts in web server logs.
• Implement network segmentation to limit the scope of potential compromise in case of successful exploitation, mitigating the “scope change” impact mentioned in the overview.
• Monitor outbound network connections originating from ORDS servers for unusual activity after patching, which could indicate post-exploitation activity.