CVE-2026-20256 Details
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.
A vulnerability exists in Splunk Enterprise versions prior to 10.2.4, 10.0.7, 9.4.12, and 9.3.13, as well as in Splunk Cloud Platform versions prior to 10.3.2512.13, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132. In these versions, a low-privileged user without 'admin' or 'power' roles could exfiltrate data through classic dashboards. This is achieved by using a protocol-relative URL in a drill-down link to redirect a victim to an external site. The vulnerability arises because the URL classifier in classic dashboards only accepts 'http://' and 'https://' schemes when evaluating external URLs. As a result, protocol-relative URLs like '//attacker.com' can bypass this validation, and Splunk Web fails to present the external-navigation warning dialog to the user.
Users should upgrade to Splunk Enterprise versions 10.4.0, 10.2.4, 10.0.7, 9.4.12, and 9.3.13. For Splunk Cloud Platform, instances are actively monitored and patched by Splunk.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 10, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://advisory.splunk.com/advisories/SVD-2026-0606 | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-20 | Improper Input Validation | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| splunk splunk | >= 9.3.0, < 9.3.13 >= 9.4.0, < 9.4.12 >= 10.0.0, < 10.0.7 >= 10.2.0, < 10.2.4 |
CPE
Remediation
| |
| splunk splunk cloud platform | >= 9.3.2411, < 9.3.2411.132 >= 10.1.2507, < 10.1.2507.23 >= 10.2.2510, < 10.2.2510.15 >= 10.3.2512, < 10.3.2512.13 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 15, 2026 | Initial Analysis | [email protected] |
| Jun 10, 2026 | New CVE Received | [email protected] |