Description
Unblu Spark contains an open redirect vulnerability that can be escalated to a DOM-based cross-site scripting (XSS) attack. When Unblu Spark is deployed with com.unblu.identifier.siteEmbeddedSetup=true, it runs in the same origin as the host application. Any JavaScript injected through this vulnerability therefore executes with full access to the host application's cookies, DOM, and same-origin APIs — an attacker can reach all resources of the host application, not just Unblu's. This expanded blast radius is the reason on-premises deployments using this configuration are rated CRITICAL.
References1
Metrics
- CVSS 4.0
-
9.3
CRITICAL
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 36 · as of 14 November 2026
- CWE
- CWE-79CWE-601
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.