CVE-2026-20255: splunk Improper Input Validation
Vulnerability summary
CVE-2026-20255 is a medium (CVSS 5.7) Improper Input Validation vulnerability in splunk. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 27.2% of scored vulnerabilities.
Timeline
- 10-06-2026PublishedVulnerability first disclosed.
- 10-06-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST5.7MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.35%
Chance of exploitation in the next 30 days
Percentile
27%
Versus all other CVEs
30-day change
0.00 pp
From 0.35% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Splunk3 products
- splunk≥ 9.3.0, < 9.3.13 | ≥ 9.4.0, < 9.4.12 | ≥ 10.0.0, < 10.0.7 | ≥ 10.2.0, < 10.2.4
- splunk_cloud_platform≥ 9.3.2411, < 9.3.2411.132 | ≥ 10.1.2507, < 10.1.2507.23 | ≥ 10.2.2510, < 10.2.2510.15 | ≥ 10.3.2512, < 10.3.2512.13
- splunk enterprise≥ 10.2, < 10.2.4 | ≥ 10.0, < 10.0.7 | ≥ 9.4, < 9.4.12 | ≥ 9.3, < 9.3.13
1 vendor · 3 products
References
1 links- advisory.splunk.com/advisories/SVD-2026-0605Vendor Advisory