Resource exhaustion in Splunk
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.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.049 (91.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Splunk
- Splunk Cloud Platform — versions 10.2.2510, 10.1.2507, 10.0.2503
- Splunk Splunk_cloud_platform
- Splunk Enterprise — versions 10.0, 9.4, 9.3
Weakness classification (CWE)
References
- psirt@cisco.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20139?
- CVE-2026-20139 is a medium-severity vulnerability in Splunk, classified under Uncontrolled Resource Consumption. CVSS score: 4.3/10. Published 2026-02-18.
- How severe is CVE-2026-20139?
- Medium severity. CVSS v3 base score is 4.3 out of 10.