Splunk Enterprise's Missing Authentication on a PostgreSQL Sidecar Service Endpoint Lets Unauthenticated Users Create or Truncate Arbitrary Files; CISA's June 21st KEV Deadline Has Passed

Last refreshed2026-09-27

Status: KEV | Advisory ID: CVE-2026-20253

Key Details

CVE	CVE-2026-20253
Vulnerability Name	Splunk Enterprise Missing Authentication for Critical Function Vulnerability
Affected products	Splunk Enterprise
Exploitation status	Listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation.
Classified as	CWE-306 (Missing Authentication for Critical Function)
KEV listing	Added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-06-18.
Exploitation prediction (EPSS)	96.94% probability of exploitation in the next 30 days (100% percentile) -- FIRST.org's EPSS model.
Federal remediation deadline	2026-06-21 (CISA KEV, Binding Operational Directive).

Affected Products, Subsystems & Sectors

Vendor	Product	Affected Versions	Patch Status
Splunk	Enterprise

Vendor

Product

Affected Versions

Patch Status

Splunk

Enterprise

Subsystems	General OT
Sectors	Multiple

What to Know

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.

What to Do

Monitor Splunk's web page for any future patch releases.

References

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-20253
CVE	https://www.cve.org/CVERecord?id=CVE-2026-20253

Source

Reference

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-20253

CVE

https://www.cve.org/CVERecord?id=CVE-2026-20253

KEV Required Action

Field	Value
KEV Link	https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Date Added to KEV	2026-06-18
Required Action Due Date	2026-06-21
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.

Field

Value

KEV Link

https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Date Added to KEV

2026-06-18

Required Action Due Date

2026-06-21

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.