CVE-2026-20256 (GCVE-0-2026-20256)
Vulnerability from cvelistv5 – Published: 2026-06-10 17:15 – Updated: 2026-06-10 18:19
VLAI
Title
Improper Input Validation through Protocol-Relative URL in Classic Dashboards in Splunk Enterprise
Summary
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.
Severity
5.7 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-20 - The product does not validate or incorrectly validates input that can affect the control flow or data flow of a program.
Assigner
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Splunk | Splunk Enterprise |
Affected:
10.2 , < 10.2.4
(custom)
Affected: 10.0 , < 10.0.7 (custom) Affected: 9.4 , < 9.4.12 (custom) Affected: 9.3 , < 9.3.13 (custom) |
|
| Splunk | Splunk Cloud Platform |
Affected:
10.3.2512 , < 10.3.2512.13
(custom)
Affected: 10.2.2510 , < 10.2.2510.15 (custom) Affected: 10.1.2507 , < 10.1.2507.23 (custom) Affected: 9.3.2411 , < 9.3.2411.132 (custom) |
Date Public
2026-06-10 00:00
Credits
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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