CVE-2026-76354 Splunk CVE debrief

Who should care

Splunk Enterprise administrators, particularly those with versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, should be aware of this vulnerability and take steps to mitigate it. This includes patching vulnerable versions, restricting access to the REST API for users without 'admin' or 'power' roles, and monitoring for unusual activity on non-captain search head cluster members. Additionally, operators, platform administrators, vulnerability management teams, and security teams should review the vulnerability's impact on their environments and plan accordingly. Those responsible for managing Splunk Enterprise instances should ensure that they are running a patched version to prevent potential system integrity and availability impacts. Security teams should also review compensating controls for exposed systems while remediation is scheduled and verified. Monitoring and detection teams should check relevant logs for exposed assets that need extra review. Asset inventory managers should track exceptions and retest remediated assets, and close the item only after evidence is documented. Change management teams should plan vendor-supported updates or mitigations through normal change control where exposure is confirmed. Those tracking vulnerabilities should verify that affected product deployments exist in managed environments and assign an owner for follow-up. They should also review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. This will help ensure that all necessary steps are taken to mitigate the vulnerability and prevent potential impacts on system integrity and availability. The vulnerability's potential impact on system integrity and availability makes it essential for administrators to prioritize patching and take proactive measures to prevent exploitation. By doing so, they can help protect their environments from potential attacks and maintain the security and reliability of their Splunk Enterprise instances. Furthermore, it is crucial for administrators to stay informed about the vulnerability and its potential impact, as well as to stay up-to-date with the latest patches and updates. This will help

Technical summary

In Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, a user without 'admin' or 'power' roles can send crafted REST API requests to delete or overwrite files writable by the user account running Splunk processes on non-captain search head cluster members. This vulnerability arises from Search Head Clustering bundle replication not validating replicated bundle file names or neutralizing NUL bytes before constructing member bundle paths. Administrators should prioritize patching vulnerable versions to prevent potential system integrity and availability impacts.

Defensive priority

Administrators of Splunk Enterprise instances should prioritize patching vulnerable versions to prevent potential system integrity and availability impacts.

Recommended defensive actions

• Patch Splunk Enterprise to version 10.4.2, 10.2.6, 10.0.9, or 9.4.14.
• Restrict access to the REST API for users without 'admin' or 'power' roles.
• Monitor for unusual activity on non-captain search head cluster members.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The vulnerability exists in Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14. A user without 'admin' or 'power' roles could affect system integrity and availability by sending a crafted REST API request that deletes or temporarily overwrites files. The issue arises from Search Head Clustering bundle replication not validating replicated bundle file names or neutralizing NUL bytes before constructing member bundle paths.

Official resources