CVE-2026-62595: Oracle Siebel CRM Auth Bypass Vulnerability

CVE-2026-62595 Overview

CVE-2026-62595 is an access control vulnerability [CWE-284] in the Open Integration component of Oracle Siebel CRM Integration. The flaw affects supported versions 25.12 through 26.6. An unauthenticated attacker with access to the adjacent network segment can compromise the Siebel CRM Integration service without user interaction. Successful exploitation permits unauthorized creation, deletion, or modification of critical data, along with full read access to all Siebel CRM Integration accessible data. Oracle addressed the issue in its August 2026 Critical Patch Update.

Critical Impact
An adjacent-network attacker can read and modify all data accessible to the Siebel CRM Integration service without authentication.

Affected Products

Oracle Siebel CRM Integration version 25.12
Oracle Siebel CRM Integration versions 26.x through 26.6
Oracle Siebel CRM Open Integration component

Discovery Timeline

2026-08-18 - CVE-2026-62595 published to NVD
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-62595

Vulnerability Analysis

The vulnerability resides in the Open Integration component of Oracle Siebel CRM Integration. This component handles inbound and outbound integration between Siebel CRM and external systems. Improper access control [CWE-284] allows requests originating from the adjacent network to bypass authorization checks. The attacker requires no privileges and no user interaction to reach the vulnerable code path.

Exploitation yields high impact on confidentiality and integrity. An attacker can read, create, modify, or delete any data accessible to the Siebel CRM Integration service. Availability is not affected, which suggests the flaw exposes data-handling operations rather than service control paths.

Root Cause

The root cause is a missing or insufficient access control check in the Open Integration component. Requests reaching the integration listener are processed without proper enforcement of authentication or authorization boundaries. This class of weakness is tracked under [CWE-284: Improper Access Control].

Attack Vector

The attack vector is Adjacent Network. The attacker must reach the physical communication segment attached to the hardware running Siebel CRM Integration. This typically means the same VLAN, broadcast domain, or directly connected network segment. Once positioned, the attacker sends crafted integration requests to the exposed service endpoint. No credentials, tokens, or user interaction are required to trigger the flaw.

Oracle has not published exploitation code, and no public proof-of-concept is available at the time of writing. Refer to the Oracle Security Alert for vendor technical guidance.

Detection Methods for CVE-2026-62595

Indicators of Compromise

Unexpected integration requests to Siebel Open Integration endpoints from hosts on the same network segment that do not normally communicate with the Siebel server
Creation, modification, or deletion of Siebel business component records without a corresponding authenticated user session
Anomalous outbound data flows from the Siebel Integration host to internal peers

Detection Strategies

Inspect Siebel application and integration audit logs for unauthenticated or session-less transactions against Open Integration interfaces
Correlate network flow data with Siebel transaction logs to identify integration calls originating from unauthorized adjacent hosts
Alert on schema-level changes to critical Siebel business objects that lack an associated authenticated user identifier

Monitoring Recommendations

Enable verbose logging on Siebel Open Integration listeners and forward events to a centralized analytics platform
Monitor east-west traffic on the VLAN hosting Siebel CRM Integration for anomalous source addresses
Baseline normal integration partner IP ranges and alert on deviations

How to Mitigate CVE-2026-62595

Immediate Actions Required

Apply the fixes provided in the Oracle August 2026 Critical Patch Update to all Siebel CRM Integration deployments running versions 25.12 through 26.6
Restrict network access to Siebel Open Integration listeners so that only known integration partner hosts can reach them
Audit recent integration activity for unauthorized data creation, modification, or deletion prior to patching

Patch Information

Oracle released the patch for CVE-2026-62595 in the August 2026 Critical Patch Update. Details and download links are available in the Oracle Security Alert. Administrators should schedule application of the update following Oracle's documented upgrade procedures for Siebel CRM.

Workarounds

Segment the Siebel CRM Integration host onto a dedicated VLAN with strict access control lists that permit only authorized integration peers
Deploy host-based firewall rules limiting inbound connections to the Open Integration service to specific source addresses
Disable the Open Integration component in environments where it is not required until the patch is applied

bash

# Example iptables rule restricting Open Integration access to a known partner host
iptables -A INPUT -p tcp --dport <siebel_integration_port> -s <trusted_partner_ip> -j ACCEPT
iptables -A INPUT -p tcp --dport <siebel_integration_port> -j DROP