CVE-2026-20253 (GCVE-0-2026-20253)

Vulnerability from cvelistv5 – Published: 2026-06-10 17:16 – Updated: 2026-06-19 03:55
VLAI CISA Previdian
Title
Unauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sidecar Service Endpoint in Splunk Enterprise
Summary
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.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: active Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-10 00:00 UTC
CWE
  • CWE-306 - The software does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
Assigner
References
Impacted products
Vendor Product Version
Splunk Splunk Enterprise Affected: 10.2 , < 10.2.4 (custom)
Affected: 10.0 , < 10.0.7 (custom)
Create a notification for this product.
Date Public
2026-06-10 00:00
Credits
Alex Hordijk (hordalex)
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 4606c2aa-0c09-455c-a706-d82082253266

Vulnerability ID: CVE-2026-20253

Status: Confirmed

Status Updated: 2026-06-18 02:00 CEST

Exploited: Yes

Timestamps
First Seen: 2026-06-18
Asserted: 2026-06-18
Scope
Notes: Splunk Enterprise Missing Authentication for Critical Function Vulnerability | Affected: Splunk / Enterprise | 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. | Due date: 2026-06-21 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): 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
Evidence

Type: Vendor Report

Signal: Successful Exploitation

Confidence: 80%

Source: cisa-kev

Details
Cwes CWE-306
Feed CISA Known Exploited Vulnerabilities Catalog
Product Enterprise
Due Date 2026-06-21
Date Added 2026-06-18
Vendorproject Splunk
Vulnerabilityname Splunk Enterprise Missing Authentication for Critical Function Vulnerability
Knownransomwarecampaignuse Unknown
References
Created: 2026-10-02 08:09 CEST | Updated: 2026-10-02 08:09 CEST
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: d2a3e024-6dda-4563-92fa-1866d3582479

Vulnerability ID: CVE-2026-20253

Status: Confirmed

Status Updated: 2026-06-15 07:15 CEST

Exploited: Yes

Timestamps
First Seen: 2026-06-15
Asserted: 2026-06-15
Scope
Notes: Unauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sidecar Service Endpoint in Splunk Enterprise | Affected: Splunk / Splunk Enterprise | CVSS: 9.8 (CRITICAL) | EPSS: 0.96939 | Used in malware: unknown | Listed 3 days ahead of CISA KEV | Not yet in CISA KEV: False
Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: previdian

Details
Feed Previdian (previdian.com)
Title Unauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sidecar Service Endpoint in Splunk Enterprise
Cve Id CVE-2026-20253
Vendor Splunk
Ghsa Id GHSA-XGM5-JH99-WC4V
Product Splunk Enterprise
Added Date 2026-06-15T05:15:25.399Z
Cvss Score 9.8
Epss Score 0.96939
Previous Ids
Cvss Severity CRITICAL
Virtual Patch True
Cvss Estimated False
Epss Percentile 0.99889
Used In Malware unknown
Vulnerability Id CVE-2026-20253
Ahead Of Cisa Kev 
{
  "count": 3,
  "unit": "day"
}
Not Yet In Cisa Kev False
References
Created: 2026-10-02 09:09 CEST | Updated: 2026-10-02 09:09 CEST
Show details on NVD website
To clipboard 

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