Auth bypass in Splunk
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 s…
Vulnerability class: Broken Authentication
EPSS: 0.962 (99.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Splunk
- Splunk Cloud Platform — versions 10.4.2604, 10.2.2510
- Splunk Enterprise — versions 10.2, 10.0
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
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.
Public proof-of-concept exploits
References
- psirt@cisco.com (Mitigation, Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Exploit, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2026-20253?
- CVE-2026-20253 is a critical-severity vulnerability in Splunk, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-06-10.
- How severe is CVE-2026-20253?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-20253 known to be exploited?
- Yes. CVE-2026-20253 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-06-18), indicating it is being actively exploited. 6 public proof-of-concept repositories are indexed.