CVE-2026-20253

What the flaw is

Splunk Enterprise contains a missing authentication for critical function vulnerability which could allow an unauthenticated user to create or truncate arbitrary files through a PostgreSQL sidecar service endpoint.

Description as published by CISA. We have not independently reproduced it.

What CISA requires

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.

This deadline is binding on US federal civilian agencies under BOD 22-01. It is not a legal deadline for anyone else, but it is a useful urgency signal — CISA sets it by how actively the flaw is being used, not by CVSS.

Public exploit code

We hold no public exploit references for this CVE. That means our dataset has none — it is not evidence that no exploit exists. CISA has confirmed this vulnerability is being exploited in the wild regardless.

Vendor advisories

• advisory.splunk.com/advisories/SVD-2026-0603
• www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-ba
• www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioriti
• nvd.nist.gov/vuln/detail/CVE-2026-20253

Primary sources

• NVD entry — CVSS score, CPE list and references
• CISA KEV catalog — the source for this page
• CVE Record at cve.org