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TI-2026-10309 Aliases CVE-2026-11964GHSA-6f2x-47pc-8mpq

User Registration & Membership < 5.2.2 - Unauthenticated PayPal Webhook Signature…

Priority HIGH 80Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.

Summary

The 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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00454 39th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix Fixed User Registration & Membership (Unknown): 5.2.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
UnknownUser Registration & Membershipbefore 5.2.25.2.2Patch availableCNA
  • User Registration & Membership VendorUnknown Affected before 5.2.2 Fixed in 5.2.2 Patch available CNA

Remediation

  • Fix · CNA User Registration & Membership (Unknown) Fixed in 5.2.2

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    User Registration & Membership 5.2.2

    2 records Highest priority Priority HIGH 2 HIGH

    Other records, highest priority first

    • TI-2026-10308 User Registration & Membership < 5.2.2 - Subscriber+ Cross-User Role and Membership Tier Modification via IDORPriority HIGH 70
    Show all 2 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-11964
  2. 2026-10-03 Alias added: GHSA-6f2x-47pc-8mpq

References

Exploit 1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences