CVE-2026-76356 in SOAR
Summary
by MITRE • 08/20/2026
In Splunk SOAR versions below 8.6.0, an unauthenticated user could spoof the source IP address in a crafted request to an Automation Broker notification endpoint and execute arbitrary code on the Splunk SOAR host. The vulnerability is possible because the Splunk SOAR Automation Broker trusts a client-supplied source IP address header as proof that the request originates from the local system. Successful exploitation can expose all relevant data, affect system integrity, and disrupt service availability. For more information see About Splunk SOAR Automation Broker (https://help.splunk.com/en/splunk-soar/splunk-automation-broker/about-splunk-soar-automation-broker/about-splunk-soar-automation-broker) in the Splunk documentation.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in Splunk SOAR versions prior to 8.6.0 represents a critical security flaw within the Automation Broker component, which serves as an intermediary for handling notifications and automating workflows across distributed environments. The core technical deficiency lies in the improper validation of network metadata during request processing. Specifically, the system relies on a client-supplied header field intended to indicate the source IP address of incoming requests without performing adequate verification against actual network layer information or implementing strict access control lists based on verified identities. This architectural oversight allows an unauthenticated attacker to craft malicious HTTP requests where they manually inject arbitrary values into this specific header field, effectively spoofing their origin as if it were coming from a trusted local system or internal service endpoint that the Automation Broker is configured to trust implicitly.
From a technical perspective, this flaw constitutes a classic case of insecure direct object references combined with insufficient input validation regarding network context. By trusting user-controllable data for critical security decisions such as authentication bypass and authorization checks, the application fails to enforce the principle of least privilege or verify the true origin of the request through more robust means like mutual TLS, signed tokens, or strict firewall rules that validate source IPs at the network level rather than relying on application-layer headers. The ability to spoof the source IP address enables an attacker to bypass authentication mechanisms entirely, as the system interprets these forged requests as legitimate internal communications. This lack of integrity checking allows for remote code execution with the privileges granted to the Splunk SOAR service account, which often possesses elevated permissions necessary to interact with underlying operating systems and execute automation playbooks.
The operational impact of this vulnerability is severe due to its potential for full system compromise. An attacker who successfully exploits this flaw can achieve arbitrary code execution on the host running the Splunk SOAR instance. This level of access facilitates comprehensive data exfiltration, allowing the theft of sensitive security orchestration artifacts, incident response playbooks, credentials stored within integrations, and potentially other confidential organizational data processed by the platform. Furthermore, the integrity of the system is compromised as attackers can modify configurations or inject malicious logic into automated workflows. Service availability may also be disrupted through denial-of-service attacks facilitated by the same vector, impacting critical security operations that rely on continuous monitoring and response capabilities provided by the SOAR environment.
This vulnerability aligns with CWE-287, which describes Improper Authentication, specifically where a system fails to correctly verify identity before granting access or executing privileged functions. It also maps closely to CWE-346 regarding Origin Validation Errors in security features that trust client-supplied information without verification. In the context of the MITRE ATT&CK framework, this exploitation technique relates to T1078 Valid Accounts if the attacker leverages stolen credentials alongside the spoofing capability, but more directly it reflects techniques associated with initial access and privilege escalation where network-level assumptions are exploited to bypass application controls. The attack vector is classified as Network-based (T1190) since it requires sending crafted requests over a network connection that reaches the vulnerable service endpoint.
To mitigate this risk, organizations running Splunk SOAR versions below 8.6.0 must immediately apply the vendor-provided patch to upgrade to version 8.6.0 or later, which addresses the flawed trust model within the Automation Broker notification handling logic. Until patches are applied, administrators should implement strict network segmentation and firewall rules that restrict access to the affected endpoints exclusively from known, trusted internal IP ranges, thereby preventing external actors from reaching the service even if they can spoof headers at the application layer. Additionally, deploying Web Application Firewalls with deep packet inspection capabilities may help detect and block requests containing anomalous or unexpected header values indicative of this specific exploitation attempt. Regular auditing of access logs for unusual patterns in source IP reporting versus actual connection origins can also aid in early detection of such abuse attempts.