CVE-2026-76258

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

MEDIUM
6.5
CVSS Score
Published: August 19, 2026 at 09:34 PM UTC
Updated: October 26, 2026 at 10:10 AM UTC
2 products affected across 1 vendorSplunkSplunk Secure Gateway

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions10.0.0 ≤ v < 10.0.910.2.0 ≤ v < 10.2.610.4.0 ≤ v < 10.4.29.4.0 ≤ v < 9.4.1410.010.210.49.4
Affected range stops below 10.0.9, so it looks safe — our inference, not a vendor statement
Affected range stops below 10.2.6, so it looks safe — our inference, not a vendor statement
Affected range stops below 10.4.2, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.4.14, so it looks safe — our inference, not a vendor statement
All versions3.10.0 ≤ v < 3.10.103.8.0 ≤ v < 3.8.713.9.0 ≤ v < 3.9.243.103.83.9
Affected range stops below 3.10.10, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.8.71, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.9.24, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMcisco
Vector?

Quick Info

StatusANALYZED
CWE
CWE-321

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