Critical · CVSS 9.3CVE-2026-9589

Unblu Spark Authorization Bypass in Configuration Cascade OperationsCVE-2026-9589

Answer in brief

CVE-2026-9589 records a Critical severity (CVSS 9.3) vulnerability in Unblu Spark Authorization Bypass in Configuration Cascade Operations. The current sources do not mark it as known exploited. The current feed maps Unblu inc./Unblu Spark (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 20, 2026Updated Oct 20, 2026Source checked Oct 20, 2026First seen by HOL Oct 20, 2026Material review Oct 20, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 9.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Unblu inc./Unblu Spark (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Unblu inc./Unblu Sparkgeneric	>=7.0 <8.37.0	8.37.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for Unblu inc./Unblu Spark.
Review the reported fix. Source-reported solution: Upgrade to Unblu Spark 8.37.2 or later. There is no fix for Unblu Spark 7.x. Unblu Cloud customers needn't take any action. The fix is already deployed in Unblu Cloud. There is no workaround for on-premises deployments.

Evidence timeline and material changes

Published upstream
Oct 20, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 20, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 20, 2026

Sources and claim methodology

Source referencedocs.unblu.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.