Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-11961 – Unauthenticated Privilege Escalation – User Registration & Membership WordPress …

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-11961 is a high-severity unauthenticated privilege escalation vulnerability in the User Registration & Membership WordPress plugin (by wpeverest), affecting all versions prior to 5.2.3. The flaw stems from missing server-side validation of the membership tier supplied at registration time, allowing any unauthenticated user to claim an arbitrary published membership role — including administrator — without restriction. With a CVSS v3.1 score of 8.1 (High), successful exploitation on a susceptible site can result in full WordPress site compromise.

Technical details

  • Root cause: The plugin does not validate that the membership tier ID submitted during public registration is one of the tiers explicitly allowed by the configured registration form. It assigns the role associated with whichever tier ID is supplied, trusting attacker-controlled input (CWE-269: Improper Privilege Management).
  • Trigger conditions: Exploitation requires that the target WordPress site has (a) the plugin installed and active with at least one public registration form enabled, and (b) at least one published membership tier mapped to an administrator-level WordPress role. This condition is not universally present, reflected in the CVSS AC:H rating, but is a realistic configuration for sites monetizing membership access.
  • Attack vector: Remote, unauthenticated — the attack is performed over the network by submitting a crafted registration request to the site’s public registration form endpoint, substituting a privileged tier ID for the one presented by the form.
  • Impact: Where an administrator-level membership tier exists, a successful attacker immediately obtains a WordPress administrator account, enabling full site takeover: arbitrary content modification, credential harvesting, plugin/theme installation, and potential server-side code execution via WordPress admin capabilities (Confidentiality: High, Integrity: High, Availability: High).

Affected software

  • User Registration & Membership WordPress plugin (slug: user-registration, author: wpeverest) — all versions prior to 5.2.3

Severity

  • CVSS v3.1 Base Score: 8.1 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Mitigation and recommended actions

  • Immediate — patch: Update the User Registration & Membership plugin to version 5.2.3 or later, which introduces proper server-side validation ensuring that only tiers explicitly permitted by the registration form can be assigned during registration. The fix is available through the WordPress plugin repository.
  • Audit: Review all active membership tiers on your WordPress installation. Any tier mapped to the administrator WordPress role represents the highest-risk configuration and should be audited regardless of plugin version.
  • If patching is delayed: Consider temporarily disabling public registration forms until the update can be applied, or restrict access to the registration endpoints at the network or WAF layer.

IONIX Status

The IONIX research team is tracking ongoing exploitation attempts and recommends immediate patching. Potentially affected assets are outlined in this post.

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge