Splunk Enterprise SHC `_internal` index leaks Duo secrets until 10.2
CVE-2026-20138 Published on February 18, 2026
Sensitive Information Disclosure in "_internal" index in Splunk Enterprise
In Splunk Enterprise versions below 10.2.0, 10.0.2, 9.4.7, 9.3.9, and 9.2.11, a user of a Splunk Search Head Cluster (SHC) deployment who holds a role with access to the Splunk `_internal` index could view the `integrationKey`, `secretKey`, and `appSecretKey` secrets, generated by [Duo Two-Factor Authentication for Splunk Enterprise](https://duo.com/docs/splunk), in plain text.
Weakness Type
Insertion of Sensitive Information into Log File
Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.
Products Associated with CVE-2026-20138
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Affected Versions
Splunk Enterprise:- Version 10.0 and below 10.0.2 is affected.
- Version 9.4 and below 9.4.7 is affected.
- Version 9.3 and below 9.3.9 is affected.
- Version 9.2 and below 9.2.11 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.