CVE WatchJul 23, 2026

CVE-2026-20253

Splunk Enterprise Missing Authentication for Critical Function Vulnerability

CVSS

9.8

Critical

EPSS

96.9%

p100

KEV

YES

Jun 18, 2026

Exploit Today

0-100

Published: Jun 10, 2026 · Last modified: Jul 23, 2026 · CWE-306

EPSS · 30d

96.2%EPSS · 30 days96.9%

2026-08-022026-08-30

KEV catalog record

Product

Splunk / Enterprise

Vulnerability

Splunk Enterprise Missing Authentication for Critical Function Vulnerability

Added to KEV

Jun 18, 2026

Remediate by

Jun 21, 2026

Known ransomware use

Summary description

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.

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.

Notes

https://advisory.splunk.com/advisories/SVD-2026-0603 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-20253

Technical 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.

Official references

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