# CVE-2026-91609: Oracle REST Data Services authentication bypass in GraphQL

Source: https://junglewise.ai/threats/cve-2026-91609-vulnerability-in-oracle-rest-data-services-component-graph-ql  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-91609 · Severity: medium · CVSS 6.5 · Published 2026-10-20

Oracle REST Data Services is a middleware layer that exposes Oracle database functionality via REST APIs, including GraphQL endpoints. A low-privileged attacker with network access can exploit this vulnerability to read sensitive data stored in the database without proper authorization. Successful exploitation grants unauthorized access to critical data accessible through the REST Data Services instance.

Technologies: [Oracle REST Data Services](https://junglewise.ai/threats/technologies/rest-data-services). Vendors: [Oracle](https://junglewise.ai/threats/vendors/oracle).

## Quick answers

**Is CVE-2026-91609 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91609 being exploited in the wild.

**How severe is CVE-2026-91609?** Medium severity, with a CVSS score of 6.5, published 20 October 2026.

**Which products and versions are affected?** Oracle REST Data Services 24.2.0 to 26.2.1.

**Is there a fix for CVE-2026-91609?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-91609 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-91609?** Check whether you run Oracle REST Data Services at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A vulnerability in the GraphQL component of Oracle REST Data Services allows a low-privileged authenticated user to bypass authorization controls via network access over HTTP. The flaw permits confidentiality impact through unauthorized data access. The vulnerability affects versions 24.2.0 through 26.2.1 and requires only network connectivity and low-level privileges to exploit.

## Affected products

- Oracle REST Data Services 24.2.0 to 26.2.1

## Timeline

- 2026-10-20: disclosed

## References

- [https://www.oracle.com/security-alerts/cpuoct2026.html](https://www.oracle.com/security-alerts/cpuoct2026.html)

## Related threats

- [Oracle REST Data Services remote code execution](https://junglewise.ai/threats/cve-2026-91610-vulnerability-in-oracle-rest-data-services-component-general)
- [Oracle REST Data Services authentication bypass in Core](https://junglewise.ai/threats/cve-2026-101494-vulnerability-in-oracle-rest-data-services-component-core)
- [Oracle REST Data Services unauthorized data access in Core](https://junglewise.ai/threats/cve-2026-101493-vulnerability-in-oracle-rest-data-services-component-core)
- [Oracle REST Data Services data access bypass in Core](https://junglewise.ai/threats/cve-2026-101386-vulnerability-in-oracle-rest-data-services-component-core)
- [Oracle REST Data Services data modification via HTTP](https://junglewise.ai/threats/cve-2026-101385-vulnerability-in-oracle-rest-data-services-component-core)