9.0
Critical
CVE-2026-121491 Fiber Admin 3.1.0 - 4.0.0 - Unauthenticated RCE via Host Header
Description
The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race against an administrator saving its settings.
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:HExploitable remotely over the network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- Interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Fiber Admin 3.1 | 3.1.0 → < 4.0.1 | 4.0.1 |