Unblu Spark Cross-Site Scripting in Embedded Co-Browsing

Summary

CVECVE-2026-14933
StatePUBLISHED
AssignerNCSC.ch
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-20 12:17:30 UTC
Updated2026-10-20 19:28:52 UTC
DescriptionCross-site scripting in the embedded co-browsing feature in Unblu inc. Unblu Spark 7.0 through 7.57.7 and 8.0 through 8.39.2, on on-premises and cloud deployments, allows an unauthenticated remote attacker in the visitor role to execute arbitrary JavaScript in the browser of an agent taking part in the attacker's co-browsing session, via content of the co-browsed page that the agent's browser renders as HTML. The JavaScript runs in the context and under the identity of the agent's session in the Agent Desk or the Single Conversation Desk. Exploitation requires an agent to join an embedded co-browsing session with the attacker. Mobile co-apping isn't affected.

Risk And Classification

Primary CVSS: v4.0 8.6 HIGH from [email protected]

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/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

Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')


VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary8.6HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS8.6HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
Passive
Confidentiality
High
Integrity
High
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Unblu Inc. Unblu Spark unaffected 8.35.2-hotfix.0 8.35.2 semver On-premises, Cloud
CNA Unblu Inc. Unblu Spark unaffected 8.37.2-hotfix.2 8.37.2 semver On-premises, Cloud
CNA Unblu Inc. Unblu Spark unaffected 8.38.2-hotfix.0 8.38.2 semver On-premises, Cloud
CNA Unblu Inc. Unblu Spark affected 7.0 7.57.7 semver On-premises, Cloud
CNA Unblu Inc. Unblu Spark affected 8.0 8.39.2 semver On-premises, Cloud
CNA Unblu Inc. Unblu Spark unaffected 8.39.3 On-premises, Cloud

References

ReferenceSourceLinkTags
docs.unblu.com/latest/security-bulletins [email protected] docs.unblu.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Kenan Karalioglu (chef_shell) via YesWeHack (en)

Additional Advisory Data

Solutions

CNA: Upgrade to Unblu Spark 8.39.3 or later, or 7.57.9 or later. The fix is also available in 8.35.2-hotfix.0, 8.37.2-hotfix.2, 8.38.2-hotfix.0 and later hotfixes of these release lines. Unblu Cloud customers needn't take any action. The fix is already deployed in Unblu Cloud. For a workaround for on-premises deployments that can't be upgraded immediately, see the security bulletin.

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