CVE-2026-76303
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AI Threat Summary
CVE-2026-76303 is a moderate vulnerability with a CVSS score of 5.7 affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
Description
In Splunk SOAR versions below 8.7.0, a user that holds a role with the install_apps capability could store attacker-controlled content that Splunk SOAR displays in app documentation by installing an app. If another user who holds a role with permission to view apps opens the app documentation, Splunk SOAR could run that content in the browser of the user who opened the app documentation. With this access, the first user could access data and make changes that the user who opened the app documentation could make. The vulnerability is possible because Splunk SOAR does not sanitize app documentation content before it displays that content. The vulnerability requires the attacker to phish the affected user by tricking them into initiating a request within their browser. The user that holds a role with the install_apps capability should not be able to exploit the vulnerability at will. For more information see Manage roles and permissions in Splunk SOAR (On-premises) (https://help.splunk.com/en/splunk-soar/soar-on-premises/administer-soar-on-premises/7.1.0/manage-your-splunk-soar-on-premises-users-and-accounts/manage-roles-and-permissions-in-splunk-soar-on-premises) and Add and configure apps and assets to provide actions in Splunk SOAR (On-premises) (https://help.splunk.com/en/splunk-soar/soar-on-premises/administer-soar-on-premises/8.6.0/manage-your-splunk-soar-on-premises-apps-and-assets/add-and-configure-apps-and-assets-to-provide-actions-in-splunk-soar-on-premises) in the Splunk documentation.
Attack Chain
Attacker scans for vulnerable versions using version banners or PoC scanners
Attacker triggers CVE-2026-76303 vulnerability with a crafted request or payload
Vulnerability exploited to perform unauthorized actions on the target system
Depending on vulnerability type, attacker achieves data access, service disruption, or code execution
MITRE ATT&CK Techniques
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params |
Remediation
Quick Facts
| CVE ID | CVE-2026-76303 |
| CVSS Score | 5.7 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N |
| Published | 2026-10-21 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |