CVE-2026-20258: Splunk Enterprise stored XSS in classic dashboard HTML panel

CVE-2026-20258 · Severity: high · CVSS 7.1 · Published 2026-06-10

A security vulnerability in Splunk's dashboarding feature allows a low-privileged user to embed malicious scripts into shared dashboards. If another user views the compromised dashboard, the script could execute in their browser, potentially allowing the attacker to steal sensitive session information or perform actions on the victim's behalf. This attack requires the victim to be tricked into interacting with a specific request, and it only affects systems where certain non-default web configurations are enabled.

Technologies: Splunk Cloud Platform. Vendors: Splunk.

Quick answers

Is CVE-2026-20258 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-20258 being exploited in the wild.
How severe is CVE-2026-20258?
High severity, with a CVSS score of 7.1, published 10 June 2026.
Which products and versions are affected?
Splunk Cloud Platform Below 10.3.2512.11, 10.2.2510.15, 10.1.2507.23, 9.3.2411.132.
Is there a fix for CVE-2026-20258?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-20258 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-20258?
Check whether you run Splunk Cloud Platform at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A stored cross-site scripting (XSS) vulnerability exists in the Splunk Web component of Splunk Enterprise and Splunk Cloud Platform. The flaw is located in the classic dashboard HTML panel, where a low-privileged user (without 'admin' or 'power' roles) can inject malicious scripts. Exploitation requires the 'dashboard_html_allow_embeddable_content' setting in web.conf to be set to 'true' (it is 'false' by default). An attacker must also use social engineering to trick a victim into initiating a specific request. If successful, the attacker can execute arbitrary JavaScript in the context of the victim's session. Patches are available in Splunk Enterprise versions 10.2.4, 10.0.7, 9.4.12, 9.3.13, and various Splunk Cloud Platform releases.

Affected products

  • Splunk Splunk Enterprise 9.3.0 to 9.3.12, 9.4.0 to 9.4.11, 10.0.0 to 10.0.6, 10.2.0 to 10.2.3
  • Splunk Splunk Cloud Platform Below 10.3.2512.11, 10.2.2510.15, 10.1.2507.23, 9.3.2411.132

Timeline

  • 2026-06-10: disclosed
  • 2026-06-10: advisory

References

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