Customer PII disclosure via unrestricted vendor-orders access
Published Aug 7, 2026 · Updated Aug 7, 2026
Authorization bypass in FluxBuilder MStore API before 4.21.0 allows remote authenticated users to read all WooCommerce orders and customer PII. The vendor-orders handler accepts a base64-encoded WordPress login cookie but fails to constrain its order query to records owned by that user. A Subscriber account and a plain single-vendor store with legacy order storage, or HPOS sync mode, expose names, contact details, addresses, line items, and totals for unrelated customers.
Summary
What happened
Authorization bypass in FluxBuilder MStore API before 4.21.0 allows remote authenticated users to read all WooCommerce orders and customer PII. The vendor-orders handler accepts a base64-encoded WordPress login cookie but fails to constrain its order query to records owned by that user. A Subscriber account and a plain single-vendor store with legacy order storage, or HPOS sync mode, expose names, contact details, addresses, line items, and totals for unrelated customers.
The record
- CVE
- CVE-2026-16039
- Published
- Aug 7, 2026
- Updated
- Aug 7, 2026
- Vendor
- FluxBuilder
- Product
- MStore API
- Classifications
- CWE-639, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 7, 2026CVE publishedPublication date reported by the CVE source.
- Aug 7, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <4.21.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- WPScan vendor-orders proof of conceptfunctional · validated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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