Quick answers
- Is CVE-2026-101587 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-101587 being exploited in the wild.
- How severe is CVE-2026-101587?
- Medium severity, with a CVSS score of 5.3, published 20 October 2026.
- Which products and versions are affected?
- Oracle Helidon 4.0.0 through 4.5.5, 27.0.0.
- Is there a fix for CVE-2026-101587?
- 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-2026-101587 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-101587?
- 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
The vulnerability exists in the helidon-webclient-http1 component of Helidon and allows an unauthenticated network attacker to trigger a partial denial of service condition. The HTTP/1 webclient does not properly validate or handle certain HTTP requests, allowing remote actors to cause availability impact via network-accessible HTTP. An attacker needs only network access to the HTTP endpoint; no authentication or user interaction is required.
Affected products
- Oracle Helidon 4.0.0 through 4.5.5, 27.0.0
Timeline
- 2026-10-20: disclosed