What is 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.
The record classifies CVE-2026-20139 under weakness class CWE-400. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 234 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 4.3 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - EPSS (FIRST)
- 5.1% probability of exploitation in the next 30 days, higher than 92.2% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 5.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-02-18, last modified 2026-02-19
Is CVE-2026-20139 being exploited?
It currently carries a trending score of 28 in the Threadlinqs vulnerability feed.
Affected products and versions
- Splunk: Enterprise, Cloud Platform
How to fix CVE-2026-20139
No vendor patch reference has been recorded for CVE-2026-20139 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-20139
1 tracked threat in the Threadlinqs corpus references CVE-2026-20139, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on .