CVE-2026-61256: Oracle E-Business Suite Auth Bypass Flaw

CVE-2026-61256 Overview

CVE-2026-61256 is an access control vulnerability [CWE-284] in the Oracle Advanced Inbound Telephony component of Oracle E-Business Suite. The flaw affects supported versions 12.2.3 through 12.2.15. A low-privileged attacker with network access via HTTP can exploit the weakness without user interaction. Successful exploitation allows unauthorized update, insert, or delete access to some Oracle Advanced Inbound Telephony data, unauthorized read access to a subset of that data, and the ability to cause a partial denial of service. Oracle addressed the issue in the Oracle Critical Patch Update Advisory - July 2026.

Critical Impact
Authenticated network attackers can tamper with telephony data and degrade service availability across affected Oracle E-Business Suite deployments.

Affected Products

Oracle E-Business Suite - Advanced Inbound Telephony 12.2.3
Oracle E-Business Suite - Advanced Inbound Telephony versions 12.2.4 through 12.2.14
Oracle E-Business Suite - Advanced Inbound Telephony 12.2.15

Discovery Timeline

2026-07-21 - CVE-2026-61256 published to the National Vulnerability Database (NVD)
2026-07-22 - Last updated in NVD database
July 2026 - Oracle publishes fix in the Oracle Critical Patch Update Advisory - July 2026

Technical Details for CVE-2026-61256

Vulnerability Analysis

The vulnerability resides in the Servers component of Oracle Advanced Inbound Telephony, part of the Oracle E-Business Suite (EBS) application stack. The weakness is classified as Improper Access Control [CWE-284]. An authenticated user with low privileges can send crafted HTTP requests to the Advanced Inbound Telephony servers and reach functionality that should require higher authorization. This grants the attacker the ability to read a subset of application data, modify or delete other data, and interrupt normal service operation. The Exploit Prediction Scoring System (EPSS) probability is 0.272%, indicating limited observed exploitation activity as of 2026-07-22.

Root Cause

The root cause is missing or insufficient access control enforcement on server-side endpoints exposed by Oracle Advanced Inbound Telephony. The component fails to fully validate whether the authenticated session holds the required privileges before performing data operations. This gap allows privilege boundary crossing within an authenticated session.

Attack Vector

Exploitation requires network access to the EBS deployment over HTTP and valid low-privileged credentials. No user interaction is required, and attack complexity is low. The attacker submits HTTP requests to Advanced Inbound Telephony server endpoints, targeting operations that read, insert, update, or delete telephony records. The scope remains unchanged, meaning impact is confined to the vulnerable component rather than crossing into other EBS modules.

No public proof-of-concept code has been published. Refer to the Oracle Critical Patch Update Advisory - July 2026 for authoritative technical details.

Detection Methods for CVE-2026-61256

Indicators of Compromise

Unexpected HTTP requests from low-privileged EBS accounts targeting Advanced Inbound Telephony endpoints.
Unauthorized modifications, insertions, or deletions in telephony-related tables without a corresponding administrative change ticket.
Partial service interruptions or degraded response times in the Advanced Inbound Telephony subsystem.

Detection Strategies

Enable and review Oracle E-Business Suite audit logs for Advanced Inbound Telephony data access and modification events.
Correlate application-tier HTTP access logs with database change auditing to identify privilege boundary violations.
Baseline normal telephony API usage per role and alert on deviations, especially write operations initiated by non-administrative users.

Monitoring Recommendations

Forward EBS application and middle-tier logs to a centralized SIEM or data lake with OCSF normalization for cross-source correlation.
Monitor for repeated HTTP 4xx and 5xx responses on Advanced Inbound Telephony endpoints, which can indicate probing.
Track authentication events for low-privileged accounts that suddenly access telephony administration URLs.

How to Mitigate CVE-2026-61256

Immediate Actions Required

Apply the Oracle Critical Patch Update from July 2026 to all Oracle E-Business Suite environments running Advanced Inbound Telephony versions 12.2.3 through 12.2.15.
Inventory EBS instances and confirm the Advanced Inbound Telephony component is patched to the fixed release.
Review and rotate credentials for low-privileged EBS accounts that had network access to the affected endpoints prior to patching.

Patch Information

Oracle released a fix as part of the July 2026 Critical Patch Update. Administrators should download and apply the update following the guidance in the Oracle Critical Patch Update Advisory - July 2026. Validate patch application against Oracle's published version metadata before returning systems to production.

Workarounds

Restrict network access to Advanced Inbound Telephony servers to trusted internal networks and jump hosts using firewall or reverse-proxy rules.
Enforce least-privilege role assignments in EBS and remove Advanced Inbound Telephony access from accounts that do not require it.
Enable full auditing on Advanced Inbound Telephony tables until the Critical Patch Update is deployed.

bash

# Example: restrict inbound HTTP access to EBS Advanced Inbound Telephony endpoints
# using iptables on the middle-tier host (replace with your trusted CIDR)
iptables -A INPUT -p tcp --dport 8000 -s 10.10.0.0/16 -j ACCEPT
iptables -A INPUT -p tcp --dport 8000 -j DROP