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Rontend - Security Vulnerability (CVE-2026-120070)

CVE-2026-120070

The User Frontend – Membership, User Registration, User Profile, User Directory & Content Restriction with Frontend Post Submission plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 4.3.13 via the `post_content` parameter of the `submit_post()` function. The vulnerability exists because the protected-shortcode blocklist guard inspects the `sanitize_textarea_field()` copy of the submitted `post_content`, while the copy actually persisted to the database is processed through `wp_kses()`, whose `wp_kses_no_null()` step strips C0 control bytes — allowing an attacker to inject a single `\x01` byte inside the `[wpuf-registration]` tag name to defeat the `strpos()` blocklist check while the clean, functional shortcode is stored verbatim; `strip_shortcodes()` does not neutralize the stored shortcode either, because the Frontend container that registers it via `add_shortcode()` is only instantiated when `is_admin()` is false, and `admin-ajax` requests have `is_admin() === true`. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject a `[wpuf-registration role="editor"]` shortcode into a published post, causing a live Editor-role registration form to be rendered publicly on the frontend that any visitor — or the attacker themselves — can submit to mint a WordPress Editor account with an immediately active privileged session when the default `autologin_after_registration` setting is enabled.

CVE-2026-120070

HIGH CVSS 8.8 Published 2026-10-31 Updated 2026-11-06
AI Risk High (86/100) 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:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected Components 2
Reference Links 6
AI Risk Engine High (86/100)
Exploitability High
Active Exploitation No strong signal
Published Exploit Status No public exploit references

Threat Timeline

  1. 2026-10-31 CVE published and first recorded in the threat feed.
  2. 2026-11-06 Record updated with latest vulnerability metadata.
  3. 2026-11-07 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 4 days ago

AI enriched 4 days ago (2026-11-07 20:26 UTC)

Technical Summary

The User Frontend – Membership, User Registration, User Profile, User Directory & Content Restriction with Frontend Post Submission plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 4.3.13 via the `post_content` parameter of the `submit_post()` function. The vulnerability exists because the protected-shortcode blocklist guard inspects the `sanitize_textarea_field()` copy of the submitted `post_content`, while the copy actually persisted to the database is processed through `wp_kses()`, whose `wp_kses_no_null()` step strips C0 control bytes — allowing an…

Potential Impact

Severity is HIGH (CVSS 8.8). 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 remote code execution potential.

Primary risk drivers: remote code execution potential

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 86/100 (High, High) with priority P2 Urgent. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Rontend PLUGIN · rontend Affected: <= 4.3.13 Fixed version not specified
Wp User Frontend PLUGIN · wp-user-frontend Affected: <= 4.3.13 Fixed version not specified

References

What to do about this

Patch immediately Serious, and reachable without meaningful privilege.

Fix it

Update Rontend to the latest available version.

Where the vendor has not published a fix yet, disable the plugin until they do.

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 Rontend, 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 Rontend. No account is needed to exploit this, so a public site is reachable by anyone.

How do I fix it?

Update Rontend to the latest available version. Where the vendor has not yet published a fix, remove or disable the plugin until they do. 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.