User Registration & Membership < 5.2.2 - Unauthenticated PayPal Webhook Signature Verification Bypass Leading to Membership Activation

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-11964
StatePUBLISHED
AssignerWPScan
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-13 07:16:27 UTC
Updated2026-07-13 18:05:36 UTC
DescriptionThe User Registration & Membership WordPress plugin before 5.2.2 does not verify the authenticity of incoming payment-provider webhook notifications before acting on them, allowing unauthenticated attackers to forge a payment-approved event and activate a paid membership subscription without completing a real payment.

Risk And Classification

Primary CVSS: v3.1 9.1 CRITICAL from ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS: 0.002610000 probability, percentile 0.175030000 (date 2026-07-14)

Problem Types: CWE-287 Improper Authentication

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Unknown User Registration Membership affected 5.2.2 semver Not specified

References

ReferenceSourceLinkTags
wpscan.com/vulnerability/faf55649-8f76-4abf-a6b9-0d0774e22d29 [email protected] wpscan.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Alessandro Greco aka Aleff (en)

CNA: Giovanbattista Ianni (University of Calabria - UNICAL) (en)

CNA: WPScan (en)

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