CVE-2026-121491 | BDVDB-2026-401714 Detail

Fiber Admin

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.

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact high. Attack vector: network.

Weaknesses#

CWE-94 Improper Control of Generation of Code ('Code Injection')

References#

https://wpscan.com/vulnerability/42b9773d-9c69-4435-be20-ae86f52b4608/

Exploit#

https://wpscan.com/vulnerability/42b9773d-9c69-4435-be20-ae86f52b4608/

History#

Version 12026-11-07Record published in the CVE List.

Published

Published: 2026-11-07
Last modified: 2026-11-07

Vendor information

Vendor: Not stated
Product: Fiber Admin

Score

9.0 Critical

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 34.1.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Code Injection

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
>= 3.1.0 and < 4.0.1
Fixed
4.0.1

Scoring System

CVSS v4.0

Not available

CVSS v3.1

9.0 Critical

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Metric breakdown
Attack Vector	Network
Attack Complexity	High
Privileges Required	None
User Interaction	None
Scope	Changed
Confidentiality	High
Integrity	High
Availability	High

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).