CVE-2026-20253
Critical 9.8 Exploited in the wild (KEV)
Confirmed active exploitation — CISA KEV catalog
- Name
- Splunk Enterprise Missing Authentication for Critical Function Vulnerability
- Added to catalog
- Remediation due date (US federal)
- 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.
Description
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.
Metrics
- CVSS 3.1
-
9.8 (CRITICAL)
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 97% (percentile: 100) as of 1 November 2026
- CWE
- CWE-306
Affected products
splunk: splunk
References
- https://advisory.splunk.com/advisories/SVD-2026-0603 MitigationVendor Advisory
- https://labs.watchtowr.com/why-use-app-level-auth-when-every-database-has-auth-… ExploitThird Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026… US Government Resource