CVE-2026-20255

Description

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 malicious classic dashboard that exfiltrates sensitive data to an external server. The vulnerability exists because URL validation on the external content dialog is incomplete, which can allow for requests to untrusted domains when a user interacts with a crafted dashboard.

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CVSS v3.1 Score

5.7

MEDIUM

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

EPSS — Exploit Prediction

0.0025

Probability of exploitation

0.16%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-20 Improper Input Validation

Affected Products

Vendor	Product	Versions
splunk	splunk	9.3.0 — 9.3.13
splunk	splunk	9.4.0 — 9.4.12
splunk	splunk	10.0.0 — 10.0.7
splunk	splunk	10.2.0 — 10.2.4
splunk	splunk_cloud_platform	9.3.2411 — 9.3.2411.132
splunk	splunk_cloud_platform	10.1.2507 — 10.1.2507.23
splunk	splunk_cloud_platform	10.2.2510 — 10.2.2510.15
splunk	splunk_cloud_platform	10.3.2512 — 10.3.2512.13

References

Advisories & Patches

https://advisory.splunk.com/advisories/SVD-2026-0605

Frequently Asked Questions

What is CVE-2026-20255? +

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 malicious classic dashboard that exfiltrates sensitive data to an external server. The vulnerability exists because URL validation on the external content dialog is incomplete, which can allow for requests to untrusted domains when a user interacts with a crafted dashboard. It has a CVSS v3.1 base score of 5.7 (MEDIUM).

How severe is CVE-2026-20255? +

CVE-2026-20255 has a CVSS v3.1 score of 5.7 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0025, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-20255? +

CVE-2026-20255 affects products from splunk, specifically: splunk, splunk_cloud_platform. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-20255? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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