CVE-2026-20253
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.
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- advisory.splunk.com/advisories/SVD-2026-0603MitigationVendor Advisory
- labs.watchtowr.com/why-use-app-level-auth-when-every-database-has-auth-splunk-enterprise-cve-2026-20253-pre-auth-rce/ExploitThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20253US Government Resource
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 129 days
- CVSS
- 9.8 CRITICAL
- EPSS (30-day exploit probability)
- 96.9% · top 1% of all CVEs
- Weakness
- CWE-306
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
- 1.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.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.