Actively exploited in the wild
Splunk Enterprise Missing Authentication for Critical Function Vulnerability
Splunk — Enterprise · Listed in the CISA KEV since 2026-06-18. This indicates confirmed attacks in production environments.
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CVE-2026-20253
CriticalCVSS 9.8KEVExploitation Probability (EPSS)
Very high risk95th percentile — higher than 95% of all known CVEs
Summary
In Splunk Enterprise versions 10.2 below 10.2.4 and 10 below 10.0.7, an unauthenticated user can create or truncate arbitrary files through a PostgreSQL sidecar service endpoint. The vulnerability exists due to a lack of authentication controls at this endpoint.
Risk Assessment
The organization may be exposed to unauthorized file operations, potentially leading to data loss or system integrity breaches.
Recommendation
It is recommended to immediately upgrade to a version that includes fixes. If this is not possible, disable the PostgreSQL sidecar service to mitigate the risk.
Original NVD description (English source)
In Splunk Enterprise 10.2 versions below 10.2.4 and 10 versions below 10.0.7, an unauthenticated user could create or truncate arbitrary files through a PostgreSQL sidecar service endpoint. The vulnerability exists because the PostgreSQL sidecar service endpoint lacks authentication controls, allowing any network-reachable user to invoke file operations without credentials. Splunk Enterprise versions 9.4 and earlier are not affected. If you cannot immediately upgrade to a fixed version, you can mitigate this vulnerability by disabling the PostgreSQL sidecar service.