Arbitrary Code Execution Vulnerability in Fiber Admin Plugin for WordPress
CVE-2026-121491
Currently unrated
Key Information:
- Vendor
WordPress
- Status
- Vendor
- CVE Published:
- 7 November 2026
Badges
👾 Exploit Exists🟡 Public PoC
What is CVE-2026-121491?
The Fiber Admin plugin for WordPress, prior to version 4.0.1, is vulnerable due to improper validation and escaping of request headers. This flaw allows unauthenticated attackers to exploit the system by injecting arbitrary code into a PHP file during a process where a custom database error page is active. The vulnerability arises when an attacker can successfully race against an administrator saving their settings, potentially leading to compromised site integrity.
Affected Version(s)
Fiber Admin 3.1.0 < 4.0.1
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.