Splunk Enterprise and Cloud Platform
CVE-2026-20139: Client-Side Denial of Service (DoS) through ''/splunkd/__raw/services/authentication/users/username'' REST API endpoint in Splunk Enterprise
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.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Splunk Enterprise 10.0 | 10.0.2 or later |
| Splunk Enterprise 9.4 | 9.4.8 or later |
| Splunk Enterprise 9.3 | 9.3.9 or later |
| Splunk Enterprise 9.2 | 9.2.12 or later |
| Splunk Cloud Platform 10.2 | 10.2.2510.3 or later |
| Splunk Cloud Platform 10.1 | 10.1.2507.8 or later |
| Splunk Cloud Platform 10.0 | 10.0.2503.9 or later |
| Splunk Cloud Platform 9.3 | 9.3.2411.121 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.