Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Unauthenticated, low-complexity network abuse of the checkout callback (AV:N/AC:L/PR:N/UI:N) yields fraudulent paid orders - integrity-only (I:H), no confidentiality or availability impact.
Primary rating from Vendor (WPScan).
CVSS VectorVendor: WPScan
Lifecycle Timeline
5DescriptionCVE.org
The FlxWoo WordPress plugin before 3.1.1 does not verify with the payment processor that a checkout session was actually paid before marking the associated order as paid, allowing unauthenticated attackers to complete WooCommerce orders without paying.
Articles & Coverage 1
AnalysisAI
Payment verification bypass in the FlxWoo WordPress plugin before 3.1.1 allows unauthenticated attackers to complete WooCommerce orders without paying, because the plugin marks orders as paid without confirming the checkout session was actually settled with the payment processor. Publicly available exploit code exists, and a vendor patch is released; no active exploitation is confirmed in CISA KEV. The flaw enables fraudulent free acquisition of goods or services from any store running the plugin.
Technical ContextAI
FlxWoo is an integration plugin bridging WooCommerce (the dominant WordPress e-commerce framework) with a payment flow. The root cause is CWE-287 (Improper Authentication): rather than performing a server-to-server verification (a webhook or an authenticated API callback) against the payment processor to confirm a checkout session's payment status, the plugin trusts a client-driven return/callback and transitions the order to a paid state. This is a classic broken payment-confirmation pattern where the order-completion handler accepts the success signal without validating it out-of-band with the processor of record. The CPE 'cpe:2.3:a:unknown:flxwoo' identifies the affected component as the FlxWoo application across all versions up to the fix.
RemediationAI
Vendor-released patch: upgrade the FlxWoo plugin to version 3.1.1 or later, which is available from the vendor and is the primary fix. Review the WPScan advisory (https://wpscan.com/vulnerability/b866258c-b49b-40db-a0ff-6c0921b5c89f/) for details before updating. Until 3.1.1 is deployed, deactivate the FlxWoo plugin to force payment confirmation back to WooCommerce's native/processor-verified flow (trade-off: checkout via FlxWoo is disabled, interrupting sales), or reconcile all recent orders against the payment processor's dashboard to catch orders marked paid without a matching settled transaction and hold fulfillment of unverified orders. Enabling processor-side webhook verification or manual order review for high-value items reduces fraud exposure while patching is scheduled.
Same weakness CWE-287 – Improper Authentication
View allSame technique Authentication Bypass
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-51411
GHSA-j2wf-m8xp-xm7q