Fleet Server
Monthly
Incorrect authorization in Elastic Fleet Server allows any authenticated enrolled agent to interfere with multi-part upload sessions belonging to other enrolled agents, causing a denial of service of those upload operations. Fleet Server fails to verify session ownership during chunked data uploads, meaning a low-privileged agent credential is sufficient to disrupt peer agent activity. No public exploit exists and no active exploitation has been confirmed; CVSS rates this Low (3.1) reflecting the authentication prerequisite and high complexity timing condition.
Policy information disclosure in Elastic Fleet Server allows any enrolled agent with valid credentials to retrieve policy documents it was not assigned to by substituting a client-controlled key in artifact download requests. The authorization decision relied on a client-supplied value that was persisted without being cross-checked against the server-side record of the requesting agent's actual policy assignment - a textbook CWE-639 flaw. The CVSS 3.1 score of 6.5 (AV:N/AC:L/PR:L/UI:N) reflects network-accessible, low-complexity exploitation by any authenticated agent; no public exploit has been identified at time of analysis, and the vulnerability is not listed in CISA KEV.
Code injection in Elastic Fleet Server allows an authenticated Kibana administrator to execute arbitrary server-side scripts by embedding script syntax within an output configuration identifier. Affected are all Fleet Server versions prior to those addressed in Elastic advisory ESA-2026-93, where Kibana's failure to restrict identifier characters permits injected script content to be incorporated into scripts Fleet Server constructs during routine agent policy processing. No active exploitation has been confirmed in CISA KEV and no public proof-of-concept has been identified at time of analysis, but the confidentiality and integrity impact is rated high given full script execution capability within the Fleet Server process.
Denial of service in Elastic Fleet Server (versions 8.0.0-8.19.10 and 9.0.0-9.2.4) allows remote attackers to exhaust memory by sending a specially crafted request to an upload endpoint, driving excessive allocation until the server becomes unresponsive. The flaw is a resource-throttling failure (CWE-770) with availability-only impact and no confidentiality or integrity loss. No public exploit identified at time of analysis; EPSS is low (0.30%, 22nd percentile) and CISA SSVC records no observed exploitation.
An issue was discovered in Fleet Server >= v8.10.0 and < v8.10.3 where Agent enrolment tokens are being inserted into the Fleet Server’s log file in plain text. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Incorrect authorization in Elastic Fleet Server allows any authenticated enrolled agent to interfere with multi-part upload sessions belonging to other enrolled agents, causing a denial of service of those upload operations. Fleet Server fails to verify session ownership during chunked data uploads, meaning a low-privileged agent credential is sufficient to disrupt peer agent activity. No public exploit exists and no active exploitation has been confirmed; CVSS rates this Low (3.1) reflecting the authentication prerequisite and high complexity timing condition.
Policy information disclosure in Elastic Fleet Server allows any enrolled agent with valid credentials to retrieve policy documents it was not assigned to by substituting a client-controlled key in artifact download requests. The authorization decision relied on a client-supplied value that was persisted without being cross-checked against the server-side record of the requesting agent's actual policy assignment - a textbook CWE-639 flaw. The CVSS 3.1 score of 6.5 (AV:N/AC:L/PR:L/UI:N) reflects network-accessible, low-complexity exploitation by any authenticated agent; no public exploit has been identified at time of analysis, and the vulnerability is not listed in CISA KEV.
Code injection in Elastic Fleet Server allows an authenticated Kibana administrator to execute arbitrary server-side scripts by embedding script syntax within an output configuration identifier. Affected are all Fleet Server versions prior to those addressed in Elastic advisory ESA-2026-93, where Kibana's failure to restrict identifier characters permits injected script content to be incorporated into scripts Fleet Server constructs during routine agent policy processing. No active exploitation has been confirmed in CISA KEV and no public proof-of-concept has been identified at time of analysis, but the confidentiality and integrity impact is rated high given full script execution capability within the Fleet Server process.
Denial of service in Elastic Fleet Server (versions 8.0.0-8.19.10 and 9.0.0-9.2.4) allows remote attackers to exhaust memory by sending a specially crafted request to an upload endpoint, driving excessive allocation until the server becomes unresponsive. The flaw is a resource-throttling failure (CWE-770) with availability-only impact and no confidentiality or integrity loss. No public exploit identified at time of analysis; EPSS is low (0.30%, 22nd percentile) and CISA SSVC records no observed exploitation.
An issue was discovered in Fleet Server >= v8.10.0 and < v8.10.3 where Agent enrolment tokens are being inserted into the Fleet Server’s log file in plain text. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.