CVE-2026-83030: Oracle Managed File Transfer Auth Bypass

CVE-2026-83030 Overview

CVE-2026-83030 affects the Oracle Managed File Transfer (MFT) product within Oracle Fusion Middleware, specifically the MFT Runtime Server component. Oracle disclosed the flaw in the September 2026 Critical Patch Update. A low-privileged attacker with network access via the T3 or IIOP protocols can compromise Oracle MFT with low attack complexity.

Successful exploitation allows unauthorized creation, deletion, or modification of critical data. Attackers can also read a subset of MFT-accessible data and cause a repeatable crash or hang, producing a complete denial-of-service condition. The weakness is classified under [CWE-284: Improper Access Control].

Critical Impact

Authenticated network attackers can modify or destroy data in Oracle MFT and trigger a full denial of service against the file transfer service.

Affected Products

• Oracle Managed File Transfer 12.2.1.4.0
• Oracle Managed File Transfer 14.1.2.0.0
• Oracle Fusion Middleware (MFT Runtime Server component)

Discovery Timeline

• 2026-09-15 - CVE-2026-83030 published to NVD
• 2026-09-16 - Last updated in NVD database
• September 2026 - Oracle publishes fix in the Oracle Security Alert September 2026

Technical Details for CVE-2026-83030

Vulnerability Analysis

The vulnerability resides in the MFT Runtime Server, the runtime component that processes file transfer operations for Oracle Managed File Transfer. Exploitation requires network access over the T3 or Internet Inter-ORB Protocol (IIOP) protocols used by Oracle WebLogic-based deployments. An attacker needs only low-level authenticated privileges to trigger the flaw.

Once exploited, the attacker gains write-level access to critical data managed by MFT. This includes creation, deletion, or modification of records handled by the transfer service. The attacker also gains partial read access and can force the service into a hung or crashing state, disrupting all file transfer workflows.

Root Cause

The issue is categorized as improper access control [CWE-284]. Oracle did not publish source-level detail, but the classification indicates that authorization checks within the MFT Runtime Server fail to adequately restrict privileged operations exposed through T3 and IIOP endpoints. Low-privileged authenticated sessions can invoke operations that should require higher trust.

Attack Vector

The attack path is remote and network-based. T3 and IIOP are Oracle WebLogic remoting protocols commonly exposed on ports such as 7001 and 7002 in default deployments. An attacker with valid low-privileged credentials establishes a T3 or IIOP session and issues crafted requests against the MFT Runtime Server to abuse the missing access checks.

No verified public exploit code is available for CVE-2026-83030 at the time of publication. Refer to the Oracle Security Alert September 2026 for vendor-published technical details.

Detection Methods for CVE-2026-83030

Indicators of Compromise

• Unexpected T3 or IIOP connections to WebLogic listener ports (default 7001/7002) from unusual source addresses.
• Unauthorized creation, deletion, or modification events in MFT transfer records and audit logs.
• Repeated crashes or restarts of the MFT Runtime Server process without a corresponding operational change.
• Authentication events for low-privileged MFT accounts followed by privileged operations.

Detection Strategies

• Enable WebLogic access logging and audit T3/IIOP protocol traffic against MFT-hosting managed servers.
• Correlate MFT audit trail changes with the initiating user account and source IP to spot privilege misuse.
• Baseline normal MFT administrative activity and alert on deviations initiated by non-administrative accounts.

Monitoring Recommendations

• Forward WebLogic and MFT logs into a centralized SIEM for continuous review.
• Monitor for MFT Runtime Server process restarts, out-of-memory events, and thread-pool exhaustion indicative of DoS attempts.
• Track outbound and inbound T3/IIOP traffic and alert on connections that bypass expected management networks.

How to Mitigate CVE-2026-83030

Immediate Actions Required

• Apply the fixes distributed in the Oracle September 2026 Critical Patch Update to all affected MFT installations.
• Inventory Oracle Fusion Middleware deployments and confirm all MFT 12.2.1.4.0 and 14.1.2.0.0 instances are covered.
• Restrict network exposure of WebLogic T3 and IIOP listeners to trusted management networks only.
• Rotate credentials for MFT accounts and enforce least-privilege role assignments.

Patch Information

Oracle addressed CVE-2026-83030 in the September 2026 Critical Patch Update. Administrators should download and apply the vendor-provided patches for Oracle Managed File Transfer 12.2.1.4.0 and 14.1.2.0.0 as documented in the Oracle Security Alert September 2026.

Workarounds

• Use the WebLogic Connection Filter (weblogic.security.net.ConnectionFilterImpl) to block T3 and IIOP access from untrusted sources when patching is delayed.
• Disable IIOP on managed servers hosting MFT if the protocol is not required by integrations.
• Place MFT administrative interfaces behind a VPN or jump host to eliminate direct exposure.
• Enforce strong authentication and remove unused MFT user accounts to reduce the low-privileged attack surface.

# Example WebLogic connection filter rule to restrict T3/IIOP to a trusted subnet
# Set in the WebLogic Admin Console: Security > Filter
# Connection Filter: weblogic.security.net.ConnectionFilterImpl
# Connection Filter Rules:
10.0.0.0/8 * * allow t3 t3s iiop iiops
0.0.0.0/0 * * deny  t3 t3s iiop iiops