# CVE-2026-101586: Oracle Helidon information disclosure in helidon-webclient

Source: https://junglewise.ai/threats/cve-2026-101586-vulnerability-in-the-helidon-product-of-oracle-fusion-middleware  
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-2026-101586 · Severity: medium · CVSS 5.3 · Published 2026-10-20

Helidon is a lightweight Java framework used to build web services and microservices. An unauthenticated attacker on the network can exploit a vulnerability in the helidon-webclient component to read sensitive data that the application can access. This could expose confidential information without requiring any special authentication or user interaction.

Technologies: [Oracle Helidon](https://junglewise.ai/threats/technologies/helidon). Vendors: [Oracle](https://junglewise.ai/threats/vendors/oracle).

## Quick answers

**Is CVE-2026-101586 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-101586 being exploited in the wild.

**How severe is CVE-2026-101586?** Medium severity, with a CVSS score of 5.3, published 20 October 2026.

**Which products and versions are affected?** Oracle Helidon 4.0.0-4.5.5, 27.0.0.

**Is there a fix for CVE-2026-101586?** 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-2026-101586 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-101586?** Check whether you run Oracle Helidon 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 network-accessible information disclosure vulnerability exists in the helidon-webclient component of Oracle Helidon affecting versions 4.0.0 through 4.5.5 and 27.0.0. The vulnerability allows unauthenticated attackers with network access via HTTP to read a subset of Helidon-accessible data, with no user interaction or special privileges required. The issue has been patched in newer versions.

## Affected products

- Oracle Helidon 4.0.0-4.5.5, 27.0.0

## Timeline

- 2026-10-20: disclosed

## References

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

## Related threats

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