Unblu Spark Open Redirect leading to DOM-Based XSS

published 2026-07-22 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-47656

cvss: 9.3; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

Unblu inc. Unblu Spark 8.36.1-hotfix.0, 8.37.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 3 mo ago (2026-07-22)

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	9.3	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
CNA	4.0	7.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
CNA	4.0	9.3	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

Affected products

Unblu inc. Unblu Spark

Classification

Weakness

CWE-601 URL Redirection to Untrusted Site
CWE-79 Improper Neutralization of Input During Web Page Generation

References

docs.unblu.com /latest/security-bulletins/#UBL-2026-001
vendor-advisory

Sources

CVE List CVE-2026-8152
NVD CVE-2026-8152

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary