CVE-2026-2518 — The FastX theme for WordPress is vulnerable to unauthorized
CVE-2026-2518 — 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 authen
What This Means For You
- If your environment is affected by CWE-862, review your exposure and prioritize patching based on your environment. Monitor vendor advisories for CVE-2026-2518 updates and patches.
Related ATT&CK Techniques
🛡️ Detection Rules
3 rules · 6 SIEM formats3 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
WordPress FastX Theme Unauthorized Plugin Installation - CVE-2026-2518
title: WordPress FastX Theme Unauthorized Plugin Installation - CVE-2026-2518
id: scw-2026-05-22-ai-1
status: experimental
level: high
description: |
Detects the specific AJAX action 'ultp_install_callback' used by the FastX theme to install plugins without proper authorization. This is a direct indicator of the vulnerability exploitation (CVE-2026-2518).
author: SCW Feed Engine (AI-generated)
date: 2026-05-22
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-2518/
tags:
- attack.initial_access
- attack.t1204.002
logsource:
category: webserver
detection:
selection:
cs-uri|contains:
- '/wp-admin/admin-ajax.php'
cs-uri-query|contains:
- 'action=ultp_install_callback'
cs-method|exact:
- 'POST'
sc-status|exact:
- '200'
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-2518 | vulnerability | CVE-2026-2518 |
| CWE-862 | weakness | CWE-862 |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 22, 2026 at 08:16 UTC |
This content was curated and summarized by Shimi's Cyber World for informational purposes. It is not copied or republished in full. All intellectual property rights remain with the original author and source.
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