CVE-2026-20256: The product does not validate or incorrectly validates input that can affect the control flow or data flow of a program. in Splunk 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 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.
AI Analysis
Technical Summary
This vulnerability affects 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 lacking admin or power roles can exploit the incomplete URL validation in classic dashboards to redirect users to external sites using protocol-relative URLs (e.g., //attacker.com). The URL classifier only checks for http:// and https:// schemes, so protocol-relative URLs bypass the check and do not trigger the external-navigation warning dialog in Splunk Web, potentially leading to data exfiltration.
Potential Impact
The vulnerability can lead to data exfiltration by redirecting users to attacker-controlled external sites without triggering security warnings. This could expose sensitive information accessible via classic dashboards to unauthorized external parties. The attack requires user interaction (UI:R) and a low-privileged user account (PR:L), but does not affect system integrity or availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is indicated in the provided data. Until a patch is available, restrict dashboard access to trusted users and educate users about suspicious redirects in dashboards. Monitor vendor advisories for updates on remediation.
CVE-2026-20256: The product does not validate or incorrectly validates input that can affect the control flow or data flow of a program. in Splunk Splunk Enterprise
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 v3.1
Score 5.7medium
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability affects 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 lacking admin or power roles can exploit the incomplete URL validation in classic dashboards to redirect users to external sites using protocol-relative URLs (e.g., //attacker.com). The URL classifier only checks for http:// and https:// schemes, so protocol-relative URLs bypass the check and do not trigger the external-navigation warning dialog in Splunk Web, potentially leading to data exfiltration.
Potential Impact
The vulnerability can lead to data exfiltration by redirecting users to attacker-controlled external sites without triggering security warnings. This could expose sensitive information accessible via classic dashboards to unauthorized external parties. The attack requires user interaction (UI:R) and a low-privileged user account (PR:L), but does not affect system integrity or availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is indicated in the provided data. Until a patch is available, restrict dashboard access to trusted users and educate users about suspicious redirects in dashboards. Monitor vendor advisories for updates on remediation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- cisco
- Date Reserved
- 2025-10-08T11:59:15.401Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a29aa2b1a4077f7803bb978
Added to database: 6/10/2026, 6:17:15 PM
Last enriched: 6/10/2026, 6:25:58 PM
Last updated: 6/10/2026, 8:37:25 PM
Views: 5
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