Unauthenticated REST Route Vulnerability in Fast Courier WordPress Plugin
CVE-2026-89289

Currently unrated

Key Information:

Vendor

WordPress
Status
Fast Courier
Vendor
CVE Published:
6 October 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-89289?

The Fast Courier WordPress plugin, up to version 5.2.3, contains a significant security flaw that exposes a REST API endpoint without proper authentication. This vulnerability allows unauthorized attackers to modify order fulfillment data, including the courier status and customer-facing tracking information for any WooCommerce order, simply by submitting the order ID. Such unregulated access poses a notable risk to the integrity of e-commerce transactions managed through the plugin.

Affected Version(s)

Fast Courier 0 <= 5.2.3

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-89289 - Proof of Concept

References

https://wpscan.com/vulnerability/716b6d58-a816-43f2-8a1a-...
exploitvdb-entrytechnical-description

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Enrico Marcolini - Claudio Marchesini - Dottor Marc
WPScan
.