CVE-2026-83109 Overview
CVE-2026-83109 is an information disclosure vulnerability in the Oracle Forms component of Oracle Fusion Middleware. The flaw resides in Forms Services (C/S, Charmode) and allows an unauthenticated attacker with network access via HTTP to read a subset of Oracle Forms data. Oracle assigned this vulnerability a CVSS 3.1 base score of 5.3, reflecting confidentiality impact only. The weakness is classified under [CWE-284: Improper Access Control].
Critical Impact
An unauthenticated remote attacker can retrieve a subset of Oracle Forms accessible data over HTTP without user interaction, exposing sensitive application information.
Affected Products
- Oracle Fusion Middleware - Oracle Forms version 12.2.1.19.0
- Oracle Fusion Middleware - Oracle Forms version 14.1.2.0.0
- Component: Forms Services, C/S, Charmode
Discovery Timeline
- 2026-09-15 - CVE-2026-83109 published to NVD
- 2026-09-16 - Last updated in NVD database
- 2026-09-15 - Oracle publishes Security Alert CSPUSEP2026 referencing the fix
Technical Details for CVE-2026-83109
Vulnerability Analysis
The vulnerability affects Oracle Forms Services running in client/server character mode (C/S, Charmode) within Oracle Fusion Middleware. Oracle Forms is a middleware component used to build and deploy enterprise data-entry applications backed by Oracle databases. An unauthenticated attacker can reach the vulnerable endpoint over HTTP without prior credentials or user interaction. Successful exploitation grants read access to a subset of Oracle Forms accessible data, but does not allow modification or service disruption.
Root Cause
The root cause is improper access control ([CWE-284]) within the Forms Services request handling logic. The service does not correctly enforce authorization checks before returning data over the affected HTTP interface. Because no privileges are required, the check either fails open or is missing on the exposed code path.
Attack Vector
The attack vector is fully network-based. An attacker sends crafted HTTP requests to an exposed Oracle Forms Services endpoint. No authentication token, session, or user interaction is required. The scope is unchanged, and the impact is limited to information disclosure of a subset of application data. Oracle's advisory (Security Alert CSPUSEP2026) does not publish exploit code, and no public proof-of-concept is currently available.
See the Oracle Security Alert CSPUSEP2026 for vendor-specific technical guidance.
Detection Methods for CVE-2026-83109
Indicators of Compromise
- Unauthenticated HTTP requests targeting Oracle Forms Services endpoints, particularly paths associated with C/S Charmode interfaces.
- Anomalous spikes in outbound response sizes from Forms Services hosts to untrusted client IPs.
- Access log entries showing sequential enumeration of Forms Services URLs from a single source without prior authentication.
Detection Strategies
- Inspect Oracle Fusion Middleware and Forms Services access logs for HTTP requests that return 200 OK without an authenticated session context.
- Deploy web application firewall (WAF) rules to flag or block unauthenticated access to Oracle Forms Services URIs.
- Correlate network telemetry with server logs to identify external IPs interacting with Forms Services outside of expected user populations.
Monitoring Recommendations
- Enable verbose logging on Oracle Forms Services and forward logs to a centralized SIEM for correlation and retention.
- Monitor for scanner signatures and reconnaissance patterns targeting Oracle Fusion Middleware components on TCP 80/443 and custom Forms ports.
- Alert on connections to Forms Services from network segments that should not have direct access to middleware tiers.
How to Mitigate CVE-2026-83109
Immediate Actions Required
- Apply the Oracle security update referenced in Security Alert CSPUSEP2026 to Oracle Forms 12.2.1.19.0 and 14.1.2.0.0 deployments.
- Inventory all Oracle Fusion Middleware instances and confirm whether Forms Services C/S Charmode is enabled and network-reachable.
- Restrict inbound HTTP access to Oracle Forms Services to trusted management and application networks only.
Patch Information
Oracle addressed CVE-2026-83109 in the update bundle associated with Security Alert CSPUSEP2026. Administrators should review the Oracle Security Alert CSPUSEP2026 advisory for exact patch identifiers, applicability matrices, and installation instructions for supported versions 12.2.1.19.0 and 14.1.2.0.0.
Workarounds
- Place Oracle Forms Services behind an authenticating reverse proxy that enforces access control at the edge.
- Disable the Forms Services C/S Charmode interface if it is not required by the deployment.
- Apply network segmentation and firewall rules to limit exposure of Forms Services to authorized client subnets only.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
