CVE-2026-104799

Mobile builder <= 1.4.2 - Authenticated (Subscriber+) Privilege Escalation to wcfm-profile-settings REST Route 'key'/'data' Parameters

2026-11-03 21:31
sermsak

Strategic Overview

Status
Unpatched
Affected Plugin
Mobile builder
Affected Version
<= 1.4.2
CVSS
8.8High
Weakness type
CWE-269 · Improper Privilege Management
CVE
CVE-2026-104799
View all Mobile builder vulnerabilities

At a glance

CVE-2026-104799 is a high-severity Improper Privilege Management vulnerability in the Mobile builder WordPress plugin, affecting versions <= 1.4.2. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Subscriber level or above. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed November 2026, reported by sermsak.

Vulnerability Overview

The Mobile builder plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.4.2 via the `wcfmmp_profile_settings()` REST handler exposed at `POST /mobile-builder/v1/wcfm-profile-settings`. This is due to a PHP loose-comparison logic flaw in the meta key allow-list check — `strpos( $key, 'mobile_builder' ) == 0` evaluates to `true` for any key that does *not* contain the substring `'mobile_builder'` because `strpos()` returns `false` on no match and `false == 0` is `true` in PHP — combined with a `permission_callback` (`user_permissions_check`) that grants access to any authenticated user by only verifying `$user->exists()`. This makes it possible for authenticated attackers, with Subscriber-level access and above, to pass an unsanitized `data` array via the `key` and `data` parameters directly to `update_user_meta()`, overwriting arbitrary user meta on their own account — including the `wp_capabilities` meta key — to grant themselves Administrator-level privileges.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-269: Improper Privilege Management

Mobile builder <= 1.4.2 carries this weakness at mobile_builder, and reaching it takes an account at Subscriber level or above. Improper privilege management means the code lets an account end up with capabilities its role should not have.

It converts a low-privileged account into an administrative one, which makes every other restriction on the site irrelevant. No fixed build of this plugin is recorded for Mobile builder yet, so installs running <= 1.4.2 stay exposed until the vendor ships one.

Remediation

No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.

  • Login Security
  • Alerts

External References

Related records

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