Vulnerability Report

CVE-2026-20139

Title: Client-side DoS in Splunk Web via malicious payload in user parameters

DoS

Proof Of Concept

No public PoC currently indexed for CVE-2026-20139.

CWE Category CWE-400

Published Date Feb 18, 2026

Modified Date Feb 20, 2026

Exploit Status Not Found

Score 4.3 CVSS v3.1

Exploit Probability (EPSS)

4.86%

Vulnerability Summary

CVE-2026-20139: 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.

Impacted Vendors

splunk 2

jenkins 1

Reference Links

https://advisory.splunk.com/advisories/SVD-2026-0204

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

4.3

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Associated Attack Patterns (CAPEC)

Total: Patterns