CVE-2026-54365: CentreStack before 17.3 contains an unauthenticated deserialization vulnerability in GSNamespace.dll that allows unauthenticated attackers to create arbitrary local OS user account

highCVSS 7.5CVE-2026-54365

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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 7.5
Published: 2026-07-30
Last updated: 2026-07-31
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-54365

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-543650.22% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 12% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-54365	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[NEU] [hoch] Gladinet CentreStack: Mehrere Schwachstellencert-bund

Recent advisories for CentreStack

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

high[NEU] [hoch] Gladinet CentreStack: Mehrere Schwachstellencert-bund · 2026-07-31
highCVE-2026-54368: CentreStack before 17.4 contains a SQL injection vulnerability in GladDBFiles.SearchEx() and S…nvd · 2026-07-30
highCVE-2026-54367: CentreStack before 17.2 contains an authentication bypass vulnerability that allows unauthenti…nvd · 2026-07-30
highCVE-2026-54366: CentreStack before 17.4 contains an XML external entity (XXE) injection vulnerability that all…nvd · 2026-07-30
mediumCVE-2026-54364: CentreStack before 17.4 contains a session variable injection vulnerability that allows unauth…nvd · 2026-07-30
criticalCVE-2026-54363: CentreStack before 17.5 contains a hardcoded cryptographic key vulnerability that allows unaut…nvd · 2026-07-30