Splunk Enterprise Missing Authentication for Critical Function Vulnerability
Splunk — Splunk Enterprise
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.
9.8
96.9%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- Jun 10, 2026
- Modified
- Jun 19, 2026
- Added to KEV
- Jun 18, 2026
- Federal patch due
- Jun 21, 2026
CISA 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.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2026-20253, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit — cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2026-20253 were found at last check. Absence here is not proof no exploit exists — see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2026-20253?
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.
How severe is CVE-2026-20253?
CVE-2026-20253 has a CVSS base score of 9.8 out of 10 (CVSS 3.1).
Is CVE-2026-20253 actively exploited in the wild?
Yes. CVE-2026-20253 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jun 18, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2026-20253?
96.9% - meaning FIRST.org's EPSS model estimates a 96.9% probability this vulnerability will be exploited in the wild within 30 days (100% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2026-20253?
Yes - a public Nuclei template referencing CVE-2026-20253 exist in public repositories we checked.
What type of vulnerability is CVE-2026-20253?
CVE-2026-20253 is classified under CWE-306 (The software does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.).
Cross-checked against
Impactr finds and proves whether CVE-2026-20253 — or flaws like it — are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.