CentreStack < 17.3 Unauthenticated User Creation via Deserialization in GSNamespace.dll (CVE-2026-54365) | HOL Guard CVE

High · CVSS 8.7CVE-2026-54365

CentreStack < 17.3 Unauthenticated User Creation via Deserialization in GSNamespace.dll

Answer in brief

CVE-2026-54365 records a High severity (CVSS 8.7) vulnerability in CentreStack < 17.3 Unauthenticated User Creation via Deserialization in GSNamespace.dll. The current sources do not mark it as known exploited. The current feed maps Gladinet/CentreStack (generic), Gladinet/CentreStack (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 Jul 30, 2026Updated Aug 14, 2026Source checked Sep 29, 2026First seen by HOL Aug 14, 2026Material review Aug 14, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.7
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.7. 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 Gladinet/CentreStack (generic), Gladinet/CentreStack (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Gladinet/CentreStackgeneric	>=0 <17.3	17.3
Gladinet/CentreStackgeneric	*	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Gladinet/CentreStack, Gladinet/CentreStack.
Review the reported fix. Update Gladinet/CentreStack to 17.3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 14, 2026

Sources and claim methodology

Upstream source description

CentreStack before 17.3 contains an unauthenticated deserialization vulnerability in GSNamespace.dll that allows unauthenticated attackers to create arbitrary local OS user accounts by supplying a crafted base64-encoded XML string to exposed API endpoints. Attackers can send a malicious StorageConfigure parameter to the jsonimportuserbyupn, jsonimportuserbyupnex, or japiimportuserbyupn endpoints to trigger InternalImportAdUserByUPN(), causing GladinetCloudMonitor.exe to invoke the NetUserAdd Windows API with attacker-controlled credentials and create arbitrary directories on the server filesystem.

Quoted source text, attributed separately from HOL analysis.