CVE-2026-20253
Unauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sidecar Service Endpoint in Splunk Enterprise
- Critical 9.8
- Exploited: added to CISA KEV 18 Jun 2026
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.
Key facts
- Published
- 10 Jun 2026
- Last changed
- 19 Jun 2026
- Assigned by
- cisco
- KEV added
- 18 Jun 2026
- KEV fix due
- 21 Jun 2026
- EPSS
- 96.939% likely to be exploited in the next 30 days, higher than 99.89% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: yes; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 9.8CVSS 3.1, Criticalfrom the CNA (cisco)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
What to do
- 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.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Splunk | Splunk Enterprise |
|
Timeline
- 10 Jun 2026 Published
- 18 Jun 2026 CVE-2026-20253 added to CISA KEV
- 18 Jun 2026 Added to the CISA KEV catalogue