Sensitive Information Disclosure through Log Files in Splunk Enterprise

Advisory ID: SVD-2026-0503

CVE ID: CVE-2026-20239

Published: 2026-05-20

Last Update: 2026-05-20

CVSSv3.1 Score: 7.5, High

CWE: CWE-532

Bug ID: VULN-65234

Description

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 cookies and response bodies that contain sensitive data.

The vulnerability is caused by missing output buffer sanitization in the TcpChannel component, which logs full I/O buffer contents at WARN level when discarding data during socket errors.

See About role-based user access in the Splunk documentation for more information.

Solution

Upgrade Splunk Enterprise to versions 10.2.2, 10.0.5, or higher.

Splunk is actively monitoring and patching Splunk Cloud Platform instances.

Product Status

ProductBase VersionComponentAffected VersionFix Version
Splunk Enterprise10.2splunkd10.2.0 to 10.2.110.2.2
Splunk Enterprise10.0splunkd10.0.0 to 10.0.410.0.5
Splunk Enterprise9.4splunkdNot affectedN/A
Splunk Enterprise9.3splunkdNot affectedN/A
Splunk Cloud Platform10.3.2512splunkdBelow 10.3.2512.810.3.2512.8
Splunk Cloud Platform10.2.2510splunkdBelow 10.2.2510.1110.2.2510.11
Splunk Cloud Platform10.1.2507splunkdBelow 10.1.2507.2110.1.2507.21
Splunk Cloud Platform10.0.2503splunkdBelow 10.0.2503.1310.0.2503.13

Mitigations and Workarounds

To eliminate further risk and help ensure a high level of security in your environment, review roles and capabilities on your instance and restrict _internal index access to administrator level roles. See Define roles on the Splunk platform with capabilities in the Splunk documentation for more information.

Detections

None

Severity

Splunk rates this vulnerability a 7.5, High, with a CVSSv3.1 vector of CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Acknowledgments

Charlie Huggard, Splunk