CVE-2026-76258: Splunk

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

In Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, and Splunk Secure Gateway versions below 3.10.10, 3.9.24, and 3.8.71, a user who does not hold the "admin" or "power" Splunk roles could register an arbitrary companion app and cause Splunk Secure Gateway to forward mobile user requests, including tokens that compromise all relevant data available to the affected mobile user, to an attacker-controlled Uniform Resource Locator (URL). The vulnerability is possible because a hard-coded cryptographic key in the Splunk Secure Gateway companion app registration handler allows for arbitrary callback URL registration without restriction. For more information see Define roles on the Splunk platform with capabilities (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.2/manage-splunk-platform-users-and-roles/define-roles-on-the-splunk-platform-with-capabilities) in the Splunk documentation.

Affected products

• Splunk Splunk: from 9.4.0, before 9.4.14 (fixed in 9.4.14); from 10.0.0, before 10.0.9 (fixed in 10.0.9); from 10.2.0, before 10.2.6 (fixed in 10.2.6); from 10.4.0, before 10.4.2 (fixed in 10.4.2)
• Splunk Splunk Secure Gateway: from 3.8.0, before 3.8.71 (fixed in 3.8.71); from 3.9.0, before 3.9.24 (fixed in 3.9.24); from 3.10.0, before 3.10.10 (fixed in 3.10.10)

Published 2026-08-19. Last modified 2026-08-26.