Vulnerability · Published Aug 19, 2026 · Assigned by cisco
CVE-2026-76258Use of Hard-coded Cryptographic Key through Companion App Registration in Splunk Secure Gateway
Medium 6.5
In plain English
A medium-severity security flaw in Splunk Enterprise from Splunk. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities).
Official description
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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Splunk | Splunk Enterprise | 10.4 – before 10.4.210.2 – before 10.2.610.0 – before 10.0.99.4 – before 9.4.14 |
| Splunk | Splunk Secure Gateway | 3.10 – before 3.10.103.9 – before 3.9.243.8 – before 3.8.71 |
Weakness: CWE-321 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N