How severe is CVE-2026-42398?

CVE-2026-42398 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-42398 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42398?

CVE-2026-42398 affects Elastic Kibana. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-42398?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-42398 have an EU (EUVD) identifier?

Yes. CVE-2026-42398 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33032.

When was CVE-2026-42398 published?

CVE-2026-42398 was published on 2026-05-28 and last updated on 2026-06-17.

CVE-2026-42398

CVE-2026-42398 is a high-severity vulnerability in Elastic Kibana with a CVSS 3.x base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-918.

Key facts

Severity: High (CVSS 3.x base score 7.7)
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-33032
Weakness: CWE-918
Affected product: Elastic Kibana
Published: 2026-05-28
Last modified: 2026-06-17

Description

Server-Side Request Forgery (CWE-918) in Kibana allows authenticated users with connector management privileges to bypass the operator-configured connection allowlist. By configuring a Webhook connector with a crafted target, an attacker can cause Kibana to issue outbound requests to destinations that the egress restriction controls were intended to block.

Frequently asked questions

What is CVE-2026-42398?: Server-Side Request Forgery (CWE-918) in Kibana allows authenticated users with connector management privileges to bypass the operator-configured connection allowlist. By configuring a Webhook connector with a crafted target, an attacker can cause Kibana to issue outbound requests to destinations that the egress restriction controls were intended to block.
How severe is CVE-2026-42398?: CVE-2026-42398 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-42398 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42398?: CVE-2026-42398 affects Elastic Kibana. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42398?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-42398 have an EU (EUVD) identifier?: Yes. CVE-2026-42398 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33032.
When was CVE-2026-42398 published?: CVE-2026-42398 was published on 2026-05-28 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:elastic:kibana:*:*:*:*:*:*:*:*

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