Elastic fixes 10 vulnerabilities

Do you think this report is well-written? *

Yes

Do you use this technology? *

Yes

Was this report useful to you?

Yes

We would be happy if you would describe:

The security services provided by CESNET are designed to provide significant support in ensuring the cybersecurity of connected organizations. Although we strive to provide quality and reliable services, it is not possible to guarantee absolute coverage of all security vulnerabilities. Our services should be seen as a complement to an organization's own security management, not as a replacement. The client bears ultimate responsibility for securing their environment.

This report was translated by AI; nobody has reviewed the translation yet. Original language: Czech.

[TLP:CLEAR] Elastic fixes 10 vulnerabilities

Elastic fixes 10 vulnerabilities in Kibana with versions 8.19.16, 9.2.8, 9.3.5 and 9.4.2. The most severe vulnerabilities are described below, the remaining ones can be found at [1].

Elastic Kibana - SSRF (CVE-2026-42398)

CVSS 7.7 (High)

An authenticated remote attacker with connector management privileges can, using an SSRF vulnerability and a specially crafted Webhook connector, bypass the outbound connection control defined in the xpack.actions.allowedHosts configuration and send requests to blocked destinations [2].

The vulnerability is present in product:

Kibana; >=9.0.0, <=9.2.7; >=9.3.0, <=9.3.1

CVSS: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

More information:

CVE-2026-42398 at cve.org, NVD
CWE-918: Server-Side Request Forgery (SSRF) at cwe.mitre.org

The vulnerability was publicly disclosed 28. 5. 2026.

Elastic Kibana - Privilege escalation, unauthorized read/write (CVE-2026-49095)

CVSS 6.5 (Medium)

An authenticated remote attacker with Fleet management privileges (fleet-all) can, due to insufficient input validation, escalate the privileges of Elastic Agents without authorization and thereby gain read and write access to sensitive Elasticsearch security indices [3].

The vulnerability is present in product:

Kibana; >=8.0.0, <=8.19.15; >=9.0.0, <=9.3.4; >=9.4.0, <=9.4.1

CVSS: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

More information:

CVE-2026-49095 at cve.org, NVD
CWE-20: Improper Input Validation at cwe.mitre.org

The vulnerability was publicly disclosed 28. 5. 2026.

Links

By CESNET, z.s.p.o. Táňa Macháčková on 2. 6. 2026.

Report feedback

[TLP:CLEAR] Elastic fixes 10 vulnerabilities

Elastic Kibana - SSRF (CVE-2026-42398)

CVSS 7.7 (High)

Elastic Kibana - Privilege escalation, unauthorized read/write (CVE-2026-49095)

CVSS 6.5 (Medium)

Links