Description

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

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-13T20:17:23.937Z",
  "pubdate": "2026-08-13T20:17:23.937Z",
  "executiveSummary": "An Improper Privilege Management vulnerability, classified as CWE-269, exists within Kibana Fleet, potentially leading to privilege escalation via CAPEC-233.\nThe vulnerability arises when an integration policy within Fleet declares extra data streams that the integration writes to.\nFleet subsequently incorporates these data streams into the Elasticsearch API key generated and issued to Elastic Agents enrolled in the corresponding agent policy.\nThe resulting overly permissive API key allows unauthorized insertion of new documents and the extension of index mappings for specific indices not originally intended for that agent policy.\nThe impact of this security flaw enables an attacker or compromised Elastic Agent to write arbitrary data and manipulate schema mappings within targeted Elasticsearch indices.\nHowever, the generated API key remains restricted, prohibiting the reading, updating, or deleting of existing documents.\nExploitation of this vulnerability requires the capability to configure integration policies within Kibana Fleet or compromise an existing deployment workflow to inject unauthorized data stream configurations.\nThe risk implication involves unauthorized data ingestion, index pollution, and potential mapping manipulation within the Elasticsearch cluster linked to the affected Kibana Fleet instance.",
  "technicalDetails": "The root cause of the vulnerability stems from improper privilege management in the mechanism Fleet uses to construct Elasticsearch API keys for Elastic Agents.\nSpecifically, when an integration policy is configured to declare extra data streams, the Fleet component fails to sufficiently validate or restrict these declarations.\nAs a result, Fleet automatically provisions the Elasticsearch API key associated with the Elastic Agent policy with elevated write permissions covering the specified extra data streams.\nThe vulnerable component is the Fleet integration policy management and API key generation subsystem within Kibana.\nThe attack flow proceeds as follows: First, an attacker with permissions to create or modify integration policies—or through a leveraged administrative workflow—declares malicious or unauthorized extra data streams within an integration policy.\nSecond, when an Elastic Agent enrolls or synchronizes with the corresponding agent policy, Fleet generates and transmits an Elasticsearch API key containing the expanded privileges.\nThird, the Elastic Agent utilizes this API key to interact directly with the Elasticsearch cluster.\nFourth, leveraging the expanded privileges, the payload behavior allows the insertion of new documents and the extension of index mappings for the targeted indices.\nThe technical constraints of the resulting API key dictate that while write operations and index mapping extensions are permitted, the key strictly forbids reading, updating, or deleting existing documents.\nAuthentication is required to access Kibana Fleet and manipulate integration policies, and specific privilege requirements involve roles capable of modifying Fleet agent and integration policies.\nThe post-exploitation impact is constrained by the write-only and append-only nature of the derived privileges, preventing data exfiltration or modification of historical records, but enabling potential denial of service via mapping exhaustion or data injection into unauthorized indices."
}