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 risk100th percentile - higher than 100% of all known CVEs
Summary
In Splunk Enterprise 10.2 before 10.2.4 and 10.x before 10.0.7, an unauthenticated user can create or truncate arbitrary files via a PostgreSQL sidecar service endpoint. The endpoint lacks authentication.
Risk Assessment
An attacker can manipulate system files, potentially leading to privilege escalation or disruption of Splunk.
Recommendation
Upgrade Splunk Enterprise to version 10.2.4 or 10.0.7. If not possible, disable the PostgreSQL sidecar service.
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.