Splunk Enterprise and Cloud Platform
CVE-2026-20257: Improper Input Validation through Classic Dashboard CSS in Splunk Enterprise
In Splunk Enterprise versions below 10.2.4, 10.0.7, 9.4.12, and 9.3.13, and Splunk Cloud Platform versions below 10.3.2512.13, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132, a low-privileged user that does not hold the "admin" or "power" Splunk roles could craft a classic dashboard that exfiltrates sensitive data from the browser of a higher-privileged user who views it.
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 10.2 | 10.2.4 or later |
| Splunk Enterprise 10.0 | 10.0.7 or later |
| Splunk Enterprise 9.4 | 9.4.12 or later |
| Splunk Enterprise 9.3 | 9.3.13 or later |
| Splunk Cloud Platform 10.3 | 10.3.2512.13 or later |
| Splunk Cloud Platform 10.2 | 10.2.2510.15 or later |
| Splunk Cloud Platform 10.1 | 10.1.2507.23 or later |
| Splunk Cloud Platform 9.3 | 9.3.2411.132 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
In Splunk Enterprise versions below 10.2.4, 10.0.7, 9.4.12, and 9.3.13, and Splunk Cloud Platform versions below 10.3.2512.13, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132, a low-privileged user that does not hold the "admin" or "power" Splunk roles could craft a classic dashboard that exfiltrates sensitive data from the browser of a higher-privileged user who views it.
The exfiltration is possible because classic dashboard panels do not fully validate style attribute values, which can allow for requests to reach external domains outside the configured Trusted Domains List.
The vulnerability requires the attacker to phish the victim by tricking them into initiating a request within their browser. The low-privileged user should not be able to exploit the vulnerability at will.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.