CVE-2026-76258

Use of Hard-coded Cryptographic Key through Companion App Registration in Splunk Secure Gateway

Published Aug 19, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed

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

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Splunk

Splunk Enterprise

affected

Version	Status	Constraints
`10.4`	affected	< 10.4.2
`10.2`	affected	< 10.2.6
`10.0`	affected	< 10.0.9
`9.4`	affected	< 9.4.14

Splunk

Splunk Secure Gateway

affected

Version	Status	Constraints
`3.10`	affected	< 3.10.10
`3.9`	affected	< 3.9.24
`3.8`	affected	< 3.8.71

Configuration 1 [-]

OR	cpe:2.3:a:splunk:splunk:::::enterprise:::*
	cpe:2.3:a:splunk:splunk:::::enterprise:::*
	cpe:2.3:a:splunk:splunk:::::enterprise:::*
	cpe:2.3:a:splunk:splunk:::::enterprise:::*

Configuration 2 [-]

OR	cpe:2.3:a:splunk:splunk_secure_gateway::::::::
	cpe:2.3:a:splunk:splunk_secure_gateway::::::::
	cpe:2.3:a:splunk:splunk_secure_gateway::::::::

No data.

Vendor Product Versions

Splunk

Splunk Enterprise

Version	Status	Scheme	Platform
`[10.4,10.4.2)`	affected	generic	—
`[10.2,10.2.6)`	affected	generic	—
`[10.0,10.0.9)`	affected	generic	—
`[9.4,9.4.14)`	affected	generic	—

Splunk

Splunk Secure Gateway

Version	Status	Scheme	Platform
`[3.10,3.10.10)`	affected	generic	—
`[3.9,3.9.24)`	affected	generic	—
`[3.8,3.8.71)`	affected	generic	—

Remediation

Vendor Solution

Upgrade Splunk Enterprise to versions 10.4.2, 10.2.6, 10.0.9, and 9.4.14, or higher.

Vendor Workaround

Upgrade Splunk Secure Gateway to versions 3.10.10, 3.9.24, and 3.8.71, or higher. If you are not able to upgrade Splunk Enterprise or Splunk Secure Gateway, turn off or remove the Splunk Secure Gateway app. See [Manage app and add-on objects](https://help.splunk.com/en/splunk-enterprise/administer/admin-manual/10.2/meet-splunk-apps/manage-app-and-add-on-objects) in the Splunk documentation. Note: Splunk Mobile, Spacebridge, and Mission Control rely on functionality in the Splunk Secure Gateway app. If you do not use any of these apps, features, or functionality, as a potential mitigation, you may turn off or remove the app.

Tracking

Advisories

No advisories available

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.340% probability within 30 days)

Exploitation none

Automatable no

Technical Impact partial

References

Link	Providers
https://advisory.splunk.com/advisories/SVD-2026-0801

History

Aug 26, 2026 4:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Aug 20, 2026 3:00 PM First appearance in the feed. Affected versions updated. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Splunk splunk
CPEs		cpe:2.3:a:splunk:splunk:::::enterprise:::* cpe:2.3:a:splunk:splunk_secure_gateway::::::::
Vendors & Products		Splunk splunk

Aug 19, 2026 11:30 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Splunk Splunk splunk Enterprise Splunk splunk Secure Gateway
Vendors & Products		Splunk Splunk splunk Enterprise Splunk splunk Secure Gateway

Aug 19, 2026 9:45 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
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.
Title		Use of Hard-coded Cryptographic Key through Companion App Registration in Splunk Secure Gateway
Weaknesses		CWE-321
References		https://advisory.splunk.com/advisories/SVD-2026-0801
Metrics		cvssV3_1 `{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}`