Improper input validation in Splunk
CVE-2026-20257
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.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (19.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Splunk
- Splunk Cloud Platform — versions 10.3.2512, 10.2.2510, 10.1.2507
- Splunk Cloud Platform
- Splunk Enterprise — versions 10.2, 10.0, 9.4
Weakness classification (CWE)
References
- advisory.splunk.com/advisories/SVD-2026-0607 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20257?
- CVE-2026-20257 is a medium-severity vulnerability in Splunk, classified under Improper Input Validation. CVSS score: 5.7/10. Published 2026-06-10.
- How severe is CVE-2026-20257?
- Medium severity. CVSS v3 base score is 5.7 out of 10.