What’s Vulnerable › Vulnerabilities
CVE-2026-9589: Unblu Spark Authorization Bypass in Configuration Cascade Operations
- Severity: critical (CVSS 9.3 v4.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-10-20 · updated 2026-10-20
- Weakness: CWE-639
Description
Missing authorization in the configuration cascade operations of the Collaboration Server in Unblu inc. Unblu Spark 7.0 through 8.36.1-hotfix.0, on on-premises and cloud deployments, allows an authenticated remote attacker to read and change configuration properties of entities they aren't authorized to access, including other users, other accounts and, in Unblu Cloud, other customers' accounts, via configuration read and write operations that target those entities. The Collaboration Server doesn't check whether the user reading or changing configuration has access to the entity the configuration belongs to. With certain non-default configuration validation settings, a registered user can additionally write configuration properties they aren't allowed to edit, in any scope. Exploitation requires an authenticated session but no user interaction.
Affected products
- Unblu inc. Unblu Spark: from 7.0 before 8.37.0 — fixed in 8.37.0
How to fix
Upgrade to a fixed version: Unblu inc. Unblu Spark 8.37.0. Check the vendor advisory for mitigations.
References
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