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User Registration & Membership - Security Vulnerability (CVE-2026-109870)

CVE-2026-109870

The User Registration & Membership WordPress plugin before 5.3.2 does not verify that a discount coupon applied to a paid membership plan is actually valid for that plan before treating a fully discounted order as paid, allowing unauthenticated users to be granted the role mapped to a paid plan without paying for it, which can lead to privilege escalation up to administrator where a plan is mapped to a privileged role.

CVE-2026-109870

HIGH CVSS 8.1 Published 2026-11-11 Updated 2026-11-12
AI Risk High (79/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P2 Urgent
Severity Band HIGH
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Components 1
Reference Links 1
AI Risk Engine High (79/100)
Exploitability High
Active Exploitation No strong signal
Published Exploit Status No public exploit references

Threat Timeline

  1. 2026-11-11 CVE published and first recorded in the threat feed.
  2. 2026-11-12 Record updated with latest vulnerability metadata.
  3. 2026-11-13 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 7 hours ago

AI enriched 7 hours ago (2026-11-13 19:53 UTC)

Technical Summary

The User Registration & Membership WordPress plugin before 5.3.2 does not verify that a discount coupon applied to a paid membership plan is actually valid for that plan before treating a fully discounted order as paid, allowing unauthenticated users to be granted the role mapped to a paid plan without paying for it, which can lead to privilege escalation up to administrator where a plan is mapped to a privileged role.

Potential Impact

Severity is HIGH (CVSS 8.1). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as High based on low-bar exploit prerequisites.

Primary risk drivers: low-bar exploit prerequisites

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 79/100 (High, High) with priority P2 Urgent. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

References

What to do about this

Patch immediately Serious, and reachable without meaningful privilege.

Fix it

Update User Registration & Membership to 5.3.2 or later.

That is the complete fix. Everything below is what protects you in the meantime.

Cannot update today? Unauthorised administrator detection in Hack Halt ProSecure blocks this class of attack before WordPress processes the request.

Alert when a new administrator appears or a role is escalated. Creating a hidden admin is the most common persistence step after a WordPress compromise.

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Not sure if you are affected?

Scan your site to see whether it runs User Registration & Membership, and at which version.

Free, no installation, no account. It reads what your site already publishes, then tells you which plugins carry known vulnerabilities and what to do about each one.

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Am I affected by this vulnerability?

You are affected if your site runs User Registration & Membership. Versions below 5.3.2 are vulnerable; that release and later are not. No account is needed to exploit this, so a public site is reachable by anyone.

How do I fix it?

Update User Registration & Membership to version 5.3.2 or later. That is the complete fix. Until you can update, Unauthorised administrator detection in Hack Halt ProSecure contains this class of attack at the request layer.

What can an attacker actually do?

This is a Privilege Escalation flaw. An attacker who exploits it can raise a low-privilege account, or none at all, to administrator.