CVE-2026-76390 Splunk CVE debrief

Who should care

Users of Cisco Talos Intelligence for Enterprise Security Cloud, especially those with Splunk Enterprise Security deployments, should be aware of this vulnerability. They should review their current version and consider upgrading to version 1.0.3 or later. Security teams and operators managing these deployments should prioritize reviewing and mitigating this vulnerability to prevent potential reconnaissance and unauthorized access.

Technical summary

The vulnerability exists in Cisco Talos Intelligence for Enterprise Security Cloud versions below 1.0.3, allowing unauthenticated users to access the OpenAPI specification through Splunk Web static file paths. This could enable reconnaissance of REST API endpoints and authentication model. The generated OpenAPI specification is packaged in a static file path that Splunk Web serves without authentication.

Defensive priority

Medium-priority vulnerability in Cisco Talos Intelligence for Enterprise Security Cloud, requiring prompt review and mitigation.

Recommended defensive actions

• Review and apply the vendor advisory (SVD-2026-0808) for mitigation steps.
• Verify the current version of Cisco Talos Intelligence for Enterprise Security Cloud and upgrade to version 1.0.3 or later if necessary.
• Monitor Splunk Web static file paths for unauthorized access.
• Implement additional authentication and authorization controls for REST API endpoints.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The vulnerability allows unauthenticated access to the OpenAPI specification through Splunk Web static file paths, potentially enabling reconnaissance of REST API endpoints and authentication model. This issue affects Cisco Talos Intelligence for Enterprise Security Cloud versions below 1.0.3. Users should verify their current version and upgrade to version 1.0.3 or later if necessary. The OpenAPI specification is packaged in a static file path that Splunk Web serves without authentication, leading to potential reconnaissance of the add-on REST API endpoints and authentication model.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.