FastX <= 1.0.2 - Missing Authorization to Authenticated (Subscriber+) Limited Plugin Installation and Activation
Strategic Overview
- Status
- Unpatched
- Affected Theme
- FastX
- Affected Version
<= 1.0.2- CVSS
- 4.3Medium
- Weakness type
- CWE-862 · Missing Authorization
- CVE
CVE-2026-2518
At a glance
CVE-2026-2518 is a medium-severity Missing Authorization vulnerability in the FastX WordPress theme, affecting versions <= 1.0.2. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). 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 May 2026, reported by Itthidej Aramsri (Boeing777).
Vulnerability Overview
The FastX theme for WordPress is vulnerable to unauthorized limited plugin installation and activation due to missing capability checks on the 'ultp_install_callback' and 'ultp_activate_callback' functions in all versions up to, and including, 1.0.2. This makes it possible for authenticated attackers, with Subscriber-level access and above, to install and activate the PostX plugin.
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.
CWE-862: Missing Authorization
FastX <= 1.0.2 carries this weakness at ultp_install_callback, and reaching it takes an account at Subscriber level or above. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.
Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. No fixed build of this theme is recorded for FastX yet, so installs running <= 1.0.2 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
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C