Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Splunk | Splunk | >= 9.3.0, < 9.3.13 |
| Splunk | Splunk Cloud Platform | >= 9.3.2411, < 9.3.2411.132 |
Related Weaknesses (CWE)
References
- https://advisory.splunk.com/advisories/SVD-2026-0606Vendor Advisory
FAQ
What is CVE-2026-20256?
CVE-2026-20256 is a vulnerability with a CVSS score of 5.7 (MEDIUM). 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 ...
How severe is CVE-2026-20256?
CVE-2026-20256 has been rated MEDIUM with a CVSS base score of 5.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-20256?
Check the references section above for vendor advisories and patch information. Affected products include: Splunk Splunk, Splunk Splunk Cloud Platform.