# CVE-2026-42398: Elastic Kibana SSRF allowlist bypass in Webhook connector

Source: https://junglewise.ai/threats/cve-2026-42398-elastic-kibana-ssrf-allowlist-bypass-in-webhook-connector  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-28. Updated: 2026-05-28  
License: CC BY 4.0 with a link back

CVE-2026-42398 · Severity: high · CVSS 7.7 · Published 2026-05-28

Kibana is a data visualization and management platform for the Elastic Stack. A security flaw allows authorized users to bypass network restrictions intended to limit where Kibana can send data. By exploiting this, an attacker could force the server to communicate with internal systems or external websites that should be blocked, potentially leading to the exposure of sensitive internal information.

Technologies: [Elastic Kibana](https://junglewise.ai/threats/technologies/kibana). Vendors: [Elastic](https://junglewise.ai/threats/vendors/elastic).

## Quick answers

**Is CVE-2026-42398 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42398 being exploited in the wild.

**How severe is CVE-2026-42398?** High severity, with a CVSS score of 7.7, published 28 May 2026.

**Which products and versions are affected?** Elastic Kibana 9.0.0 to 9.2.7, 9.3.0 to 9.3.1.

**Is there a fix for CVE-2026-42398?** A patch was published on 2026-05-28: Fixed in versions 9.2.8 and 9.3.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-42398 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-42398?** Check whether you run Elastic Kibana 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 Server-Side Request Forgery (SSRF) vulnerability (CWE-918) exists in Kibana's connector management component. Authenticated users with privileges to manage connectors can bypass the 'xpack.actions.allowedHosts' configuration by crafting a specific target for a Webhook connector. This allows the attacker to force the Kibana server to initiate outbound requests to restricted destinations. The vulnerability affects Kibana versions 9.0.0 through 9.2.7 and 9.3.0 through 9.3.1. It has been patched in versions 9.2.8 and 9.3.2.

## Affected products

- Elastic Kibana 9.0.0 to 9.2.7, 9.3.0 to 9.3.1

## Timeline

- 2026-05-28: disclosed
- 2026-05-28: advisory
- 2026-05-28: patched: Fixed in versions 9.2.8 and 9.3.2

## References

- [https://discuss.elastic.co/t/kibana-9-2-8-and-9-3-2-security-update-esa-2026-37/386557](https://discuss.elastic.co/t/kibana-9-2-8-and-9-3-2-security-update-esa-2026-37/386557)

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- [Elastic Kibana authorization bypass in connector logs](https://junglewise.ai/threats/cve-2026-115295-authorization-bypass-through-user-controlled-key-cwe-639-in)
- [Elastic Kibana path traversal in Fleet feature](https://junglewise.ai/threats/cve-2026-115294-improper-limitation-of-a-pathname-to-a-restricted-directory-cwe)
- [Elastic Kibana credential disclosure in Observability onboarding](https://junglewise.ai/threats/cve-2026-115293-insertion-of-sensitive-information-into-sent-data-cwe-201-in)
- [Elastic Kibana authorization bypass in Machine Learning](https://junglewise.ai/threats/cve-2026-115292-authorization-bypass-through-user-controlled-key-cwe-639-in)
- [Elastic Kibana incorrect authorization in Fleet settings](https://junglewise.ai/threats/cve-2026-102412-incorrect-authorization-cwe-863-in-kibana-can-lead-to-sensitive)