CVE-2026-20204 Splunk CVE debrief

Who should care

Splunk Enterprise and Splunk Cloud Platform administrators and users with low-privileged access should assess exposure and prioritize patching vulnerable versions. They should also verify inventory for exposure, monitor for suspicious activity, and review user access and privileges.

Why it matters

A low-privileged user could potentially perform Remote Code Execution (RCE) in Splunk Enterprise and Splunk Cloud Platform versions due to improper handling of temporary files. Defenders should prioritize patching vulnerable versions and verify inventory for exposure.

• Verify inventory for exposure to vulnerable versions
• Patch vulnerable versions to prevent potential Remote Code Execution
• Monitor for suspicious activity
• Verify user access and privileges

Technical summary

The vulnerability exists due to improper handling and insufficient isolation of temporary files within the `apptemp` directory, allowing a low-privileged user to potentially perform Remote Code Execution (RCE) by uploading a malicious file to the `$SPLUNK_HOME/var/run/splunk/apptemp` directory. Affected versions include Splunk Enterprise below 10.2.1, 10.0.5, 9.4.10, and 9.3.11, and Splunk Cloud Platform versions below 10.4.2603.0, 10.3.2512.5, 10.2.2510.9, 10.1.2507.19, 10.0.2503.13, and 9.3.2411.127. The CVSS score is 7.1 and the severity is HIGH.

Defensive priority

Defenders should prioritize patching vulnerable versions of Splunk Enterprise and Splunk Cloud Platform, and verify inventory for exposure.

Recommended defensive actions

• Patch vulnerable versions of Splunk Enterprise and Splunk Cloud Platform
• Verify inventory for exposure
• Monitor for suspicious activity
• Verify user access and privileges
• 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 CVE record and NVD vulnerability detail provide information on the vulnerability, affected versions, and CVSS score. A low-privileged user could potentially perform Remote Code Execution (RCE) in Splunk Enterprise and Splunk Cloud Platform versions due to improper handling of temporary files. Defenders should verify inventory for exposure and prioritize patching vulnerable versions. The CVE record was published on 2026-04-15T16:16:34.490Z and has not been modified since then. Evidence is limited to public sources and may not be up

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.