Splunk Enterprise
Splunk Enterprise is affected by a critical-severity vulnerability (CVE-2026-20253) that is confirmed to be actively exploited in the wild. 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.
What is this vulnerability?
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 it works
This is classified as Missing Authentication. In plain terms, an attacker could use this flaw in Enterprise to gain access, disrupt service, or steal data — the exact impact depends on how it’s deployed in your environment.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
Mitigations
- Apply the vendor’s security patch or update as soon as it’s available and tested.
- If no patch exists yet, apply the vendor’s temporary workaround.
- Limit network exposure of the affected system until it’s patched.
- Review logs for signs of prior exploitation, especially if it’s flagged for ransomware use.
Recommendations
- Confirm whether Splunk Enterprise is used anywhere in your environment.
- Patch internet-facing systems first, then internal ones.
- Set a reminder ahead of the remediation deadline so it doesn’t slip.
- Subscribe to the vendor’s security advisories for earlier warning next time.
Compiled from public threat intelligence (CISA Known Exploited Vulnerabilities catalog and the National Vulnerability Database, referenced in 3 public advisories).