CVE-2026-20256
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 …
Impact
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 cause data exfiltration through classic dashboards by redirecting a victim to an external site using a protocol-relative URL in a drill-down link.<br><br>The vulnerability exists because the URL classifier in classic dashboards only recognizes `http://` and `https://` schemes when checking for external URLs. Protocol-relative URLs such as `//attacker.com` bypass this check entirely, and Splunk Web does not show the external-navigation warning dialog to the victim.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Splunk | Splunk | from 9.3.0 before 9.3.13 from 9.4.0 before 9.4.12 from 10.0.0 before 10.0.7 from 10.2.0 before 10.2.4 |
| Splunk | Splunk Cloud Platform | from 9.3.2411 before 9.3.2411.132 from 10.1.2507 before 10.1.2507.23 from 10.2.2510 before 10.2.2510.15 from 10.3.2512 before 10.3.2512.13 |