CVE-2026-20257 MEDIUM

CVE-2026-20257: Improper Input Validation through Classic Dashboard CSS in Splunk Enterprise

Vendor Splunk
Product Splunk Enterprise
Weakness CWE-20 · Input validation
Published June 10, 2026
Last update June 10, 2026

CVSS base score

5.7/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction Required
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

In Splunk Enterprise versions below 10.2.4, 10.0.7, 9.4.12, and 9.3.13, and Splunk Cloud Platform versions below 10.3.2512.13, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132, a low-privileged user that does not hold the "admin" or "power" Splunk roles could craft a classic dashboard that exfiltrates sensitive data from the browser of a higher-privileged user who views it. The exfiltration is possible because classic dashboard panels do not fully validate style attribute values, which can allow for requests to reach external domains outside the configured Trusted Domains List. The vulnerability requires the attacker to phish the victim by tricking them into initiating a request within their browser. The low-privileged user should not be able to exploit the vulnerability at will.

Key dates

02Disclosure timeline

June 10, 2026 CVE published
June 10, 2026 Record updated