Fiber Admin 3.1.0 - 4.0.0 - Unauthenticated RCE via Host Header

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-121491
StatePUBLISHED
AssignerWPScan
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-07 06:16:58 UTC
Updated2026-11-10 16:28:46 UTC
DescriptionThe 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.

Risk And Classification

Primary CVSS: v3.1 9 CRITICAL from ADP

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

EPSS: 0.003950000 probability, percentile 0.339960000 (date 2026-11-09)

Problem Types: CWE-94 | CWE-94 Improper Control of Generation of Code ('Code Injection') | CWE-94 CWE-94 Improper Control of Generation of Code ('Code Injection')

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED9CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary9CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS v3.1 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Unknown Fiber Admin affected 3.1.0 4.0.1 semver Not specified

References

ReferenceSourceLinkTags
wpscan.com/vulnerability/42b9773d-9c69-4435-be20-ae86f52b4608 [email protected] wpscan.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Naoki Kawahigashi (en)

CNA: WPScan (en)

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