CVE-2026-20138 Sensitive Information Disclosure in "_internal" index in Splunk Enterprise
Users with access to the _internal index in Splunk Search Head Clusters can view Duo authentication secrets in plain text.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-20138?
CVE-2026-20138 is a medium-severity vulnerability in Splunk Splunk, published on 18 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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: CWE-532
Which versions are affected by CVE-2026-20138?
It affects 1 product.
Products include Splunk Splunk.
How do I fix CVE-2026-20138?
No fix has been published for CVE-2026-20138 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-20138 being exploited?
There is no known exploitation of CVE-2026-20138 in the wild and no public exploit code.
Other vulnerabilities in Splunk Splunk
- CVE-2026-20253 Splunk Enterprise Missing Authentication for Critical Function
- CVE-2026-76268 Missing Authentication for Critical Function in the Patroni REST API in Splunk Enterprise
- CVE-2026-76284 Improper Neutralization in Splunk Enterprise
- CVE-2026-76285 Improper Adherence to Coding Standards in Splunk Enterprise
- CVE-2017-17067 Auth bypass in n/a
Sources
Also known as GHSA-v8wf-h34r-55f7.