CVE-2026-20256
Improper Input Validation through Protocol-Relative URL in Classic Dashboards in Splunk Enterprise
At a glance
- Source
- NVD
- EPSS
- EPSS 0.36 % · percentile 30 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- cisco
- NVD status
- Analyzed
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 cause data exfiltration through classic dashboards by redirecting a victim to an external site using a protocol-relative URL in a drill-down link.<br><br>The vulnerability exists because the URL classifier in classic dashboards only recognizes `http://` and `https://` schemes when checking for external URLs. Protocol-relative URLs such as `//attacker.com` bypass this check entirely, and Splunk Web does not show the external-navigation warning dialog to the victim.
Weaknesses (CWE)
- CWE-20 — Improper Input Validation
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N | cisco |
| CVSS 3.1 | MEDIUM 5.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N | NVD · psirt@cisco.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-36080
- GCVE · GCVE-0-2026-20256
CERT-FR advisories
- CERTFR-2026-AVI-0736 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:splunk:splunk:*:*:*:*:enterprise:*:*:*≥ 9.3.0 < 9.3.13cpe:2.3:a:splunk:splunk:*:*:*:*:enterprise:*:*:*≥ 9.4.0 < 9.4.12cpe:2.3:a:splunk:splunk:*:*:*:*:enterprise:*:*:*≥ 10.0.0 < 10.0.7cpe:2.3:a:splunk:splunk:*:*:*:*:enterprise:*:*:*≥ 10.2.0 < 10.2.4cpe:2.3:a:splunk:splunk_cloud_platform:*:*:*:*:*:*:*:*≥ 9.3.2411 < 9.3.2411.132cpe:2.3:a:splunk:splunk_cloud_platform:*:*:*:*:*:*:*:*≥ 10.1.2507 < 10.1.2507.23cpe:2.3:a:splunk:splunk_cloud_platform:*:*:*:*:*:*:*:*≥ 10.2.2510 < 10.2.2510.15cpe:2.3:a:splunk:splunk_cloud_platform:*:*:*:*:*:*:*:*≥ 10.3.2512 < 10.3.2512.13
Affected products
| Product | Versions |
|---|---|
| Splunk · Splunk Enterprise | affected 10.2 < 10.2.4 ; affected 10.0 < 10.0.7 ; affected 9.4 < 9.4.12 ; affected 9.3 < 9.3.13 |
| Splunk · Splunk Cloud Platform | affected 10.3.2512 < 10.3.2512.13 ; affected 10.2.2510 < 10.2.2510.15 ; affected 10.1.2507 < 10.1.2507.23 ; affected 9.3.2411 < 9.3.2411.132 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |