CVE-2026-72631 in Kibana
Summary
by MITRE • 08/13/2026
Improper Privilege Management (CWE-269) in Kibana Fleet can lead to privilege escalation via Privilege Escalation (CAPEC-233). An integration policy may optionally declare extra data streams that the integration writes to, which Fleet adds to the Elasticsearch API key issued to Elastic Agents enrolled in the corresponding agent policy. The resulting key allows new documents to be inserted and index mappings to be extended for specific indices. The key does not allow reading, updating, or deleting existing documents
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Analysis
by VulDB Data Team • 08/13/2026
The vulnerability described represents a critical improper privilege management issue classified as CWE-269 within the Kibana Fleet component of Elastic Stack. This flaw enables privilege escalation through CAPEC-233 mechanisms by allowing attackers to manipulate integration policies that declare additional data streams. The core technical flaw manifests in how Fleet handles API key generation for Elastic Agents, where the system creates keys with elevated permissions beyond what is strictly necessary for agent operations. When an integration policy includes optional extra data streams, Fleet automatically incorporates these into the Elasticsearch API key issued to enrolled agents, creating a dangerous permission expansion that violates the principle of least privilege.
The operational impact of this vulnerability extends far beyond simple access control bypasses. Attackers can exploit this weakness to insert malicious documents into targeted indices and extend index mappings, effectively allowing them to modify the schema and structure of data repositories without proper authorization. This capability enables persistent threats to establish backdoors within the monitoring infrastructure, potentially compromising the integrity of security logs and observability data. The vulnerability is particularly concerning because it operates at the intersection of data ingestion and access control, where attackers can manipulate both the content and structure of indexed documents while maintaining operational stealth.
The security implications align with ATT&CK techniques focusing on privilege escalation and persistence mechanisms, specifically targeting T1078 for valid accounts and T1566 for credential access. The flaw demonstrates a classic case of over-permissive API key generation where the system fails to properly scope permissions based on actual agent requirements. Organizations using Elastic Stack deployments are particularly vulnerable as this issue affects core monitoring capabilities, potentially allowing attackers to manipulate security events and evade detection systems that rely on accurate log data. The vulnerability's exploitation requires understanding of the integration policy configuration but does not require advanced technical skills beyond standard penetration testing methodologies.
Mitigation strategies should focus on implementing stricter API key scoping mechanisms within Fleet configurations to ensure that agents only receive permissions for data streams they actually need to access. Organizations must conduct comprehensive audits of their integration policies and disable unnecessary data stream declarations in agent configurations. Regular monitoring of Elasticsearch index changes and document insertions should be implemented alongside enhanced access controls for the Kibana Fleet management interface. Additionally, implementing role-based access controls that align with the principle of least privilege and regular security assessments of API key permissions will significantly reduce the attack surface. The vulnerability underscores the importance of continuous security testing of monitoring infrastructure and proper configuration management practices to prevent unauthorized privilege escalation within critical security tooling deployments.