Kibana EUVD-2026-87792

Requires the Kibana Agent Builder feature to be in use (a newer opt-in capability, not default in older deployments) with at least one SHARED agent. The attacker must already be authenticated as a non-administrative user holding EDIT privileges on that shared agent (PR:L). Exploitation further depends on a higher-privileged user subsequently interacting with the tampered agent (UI:R) - this social/timing dependency limits reliability. Full escalation to Kibana and Elasticsearch cluster administration additionally requires that the same attacker can author workflows; without workflow-authoring rights the impact is bounded to operations executed under the victim's identity. These conditions (existing authenticated foothold, agent edit rights, victim interaction, optional workflow authoring) meaningfully constrain real-world exploitation despite the network attack vector.

The vendor CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N = 7.3 High) is internally consistent with the description: a network-reachable, low-complexity attack by an already-authenticated low-privileged user (PR:L) that requires a higher-privileged victim to interact with the tampered shared agent (UI:R). This is a genuine confused-deputy privilege-escalation issue rather than an inflated high-CVSS-but-low-risk finding, because the described impact - full administrative control of Kibana and the underlying Elasticsearch cluster when the attacker can also author workflows - represents catastrophic C:H/I:H. However, the practical risk is meaningfully gated: it requires (a) an existing authenticated foothold with edit rights on a shared agent, and (b) a privileged victim actively interacting with it. No EPSS score, no CISA KEV listing, and no public POC are present in the provided data, so there is no evidence of active or automatable exploitation - this reads as a targeted, socially-timed attack, not mass-exploitable. A:N is defensible for the direct flaw, though full cluster admin realistically enables availability impact too. Agent Builder is a newer opt-in Kibana feature, further narrowing the real-world exposed population.

An authenticated non-admin analyst with edit access to a shared Kibana Agent Builder agent plants privileged operations into that agent. When a higher-privileged user (e.g., an admin) later interacts with the shared agent, those operations execute under the victim's identity; if the attacker can also author workflows, this escalates to full administrative control of Kibana and the Elasticsearch cluster. No public exploit code is identified at the time of analysis.