Affects Elastic Stack (widely deployed); allows Fleet users to grant cluster-admin creds to agents, enabling cluster takeover — organization-wide impact.
CVE-2026-78583
Kibana auth bug lets Fleet users mint agent creds with elevated Elasticsearch cluster privileges.
Is CVE-2026-78583 being exploited?
Not confirmed. CVE-2026-78583 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.22% probability of exploitation in the next 30 days.
How severe is CVE-2026-78583?
CVE-2026-78583 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-78583?
Yes. A fix has been recorded for CVE-2026-78583. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-78583 affect?
CVE-2026-78583 affects Kibana (8.19.21, 9.4.6, 9.5.3), Elastic Agent, Elasticsearch cluster. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-78583?
Upgrade Kibana to fixed versions; rotate agent credentials and audit Fleet policies.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Privilege escalation: a Fleet user can mint Elastic Agent credentials with arbitrary Elasticsearch cluster privileges up to full admin, enabling data access or cluster takeover.
Immediate action required
- affected>= 8.0.0 and <= 8.19.20
- affected>= 9.0.0 and <= 9.4.5
- affected>= 9.5.0 and <= 9.5.2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.