VulnerabilityDeferred

CVE-2026-8152

Unblu Spark contains an open redirect vulnerability that can be escalated to a DOM-based cross-site scripting (XSS) attack.

CRITICAL 9.3EPSS 0.41%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.41%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 9.3 CRITICALCVSS: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/M
EPSS: 0.41% probability · 35th percentile
CISA KEV: Not listed
Weakness: CWE-79, CWE-601
Source: vulnerability@ncsc.ch

References

https://docs.unblu.com/latest/security-bulletins/#UBL-2026-001

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.