CVE-2026-20139

Client-Side Denial of Service (DoS) through ''/splunkd/__raw/services/authentication/users/username'' REST API endpoint in Splunk Enterprise

Severity
Medium 4.3
CVSS 3.1
Exploited
Not listed
EPSS
0.050
91.9th percentile
Discovered by
Not disclosed
Published
Feb 18, 2026
Assigned by cisco

Description

In Splunk Enterprise versions below 10.2.0, 10.0.2, 9.4.8, 9.3.9, and 9.2.12, and Splunk Cloud Platform versions below 10.2.2510.3, 10.1.2507.8, 10.0.2503.9, and 9.3.2411.121, a low-privileged user that does not hold the "admin" or "power" Splunk roles could craft a malicious payload into the `realname`, `tz`, or `email` parameters of the `/splunkd/__raw/services/authentication/users/username` REST API endpoint when they change a password. This could potentially lead to a client‑side denial‑of‑service (DoS). The malicious payload might significantly slow page load times or render Splunk Web temporarily unresponsive.

Weakness: CWE-400

Affected products

Vendor Product Category Matched by
Cisco Splunk Cloud Platform SIEM & Log Management cna-assigner
Cisco Splunk Enterprise SIEM & Log Management cna-assigner
Vendor-reported products (2)
  • Splunk · Splunk Enterprise
  • Splunk · Splunk Cloud Platform

Credit

STÖK / Fredrik Alexandersson

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