What is CVE-2026-20239?

CVE-2026-20239 is a high-severity vulnerability in Splunk, classified under Insertion of Sensitive Information into Log File. CVSS score: 7.5/10. Published 2026-05-20.

How severe is CVE-2026-20239?

High severity. CVSS v3 base score is 7.5 out of 10.

Information disclosure in Splunk

CVE-2026-20239

In Splunk Enterprise versions below 10.2.2 and 10.0.5, and Splunk Cloud Platform versions below 10.3.2512.8, 10.2.2510.11, 10.1.2507.21, and 10.0.2503.13, a user with a role that has access to the `_internal` index could view session cooki…

EPSS: 0.000 (2.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Splunk
Splunk Cloud Platform — versions 10.3.2512, 10.2.2510, 10.1.2507
Splunk Splunk_cloud_platform
Splunk Enterprise — versions 10.2, 10.0

Weakness classification (CWE)

CWE-532 — Insertion of Sensitive Information into Log File

References

psirt@cisco.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-20239?: CVE-2026-20239 is a high-severity vulnerability in Splunk, classified under Insertion of Sensitive Information into Log File. CVSS score: 7.5/10. Published 2026-05-20.
How severe is CVE-2026-20239?: High severity. CVSS v3 base score is 7.5 out of 10.