CVE-2026-26747

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-26747
A Host Header Poisoning vulnerability exists in Monica 4.1.2 due to improper handling of the HTTP Host header in app/Providers/AppServiceProvider.php, combined with the default misconfiguration where the "app.force_url" is not set and default is "false". The application generates absolute URLs (such as those used in password reset emails) using the user-supplied Host header. This allows remote attackers to poison the password reset link sent to a victim,

9.1 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References
Link Resource
https://github.com/hungnqdz/cve-research/blob/main/CVE-2026-26747.md Exploit Vendor Advisory
https://github.com/monicahq/monica Product
Configurations

Configuration 1 (hide)

cpe:2.3:a:monicahq:monica:4.1.2:*:*:*:*:*:*:*
History

26 Feb 2026, 02:42

Type Values Removed Values Added
First Time Monicahq monica
Monicahq
Summary
  • (es) Una vulnerabilidad de envenenamiento de encabezado Host existe en Monica 4.1.2 debido a un manejo inadecuado del encabezado HTTP Host en app/Providers/AppServiceProvider.php, combinado con la configuración errónea predeterminada donde 'app.force_url' no está configurado y su valor predeterminado es 'false'. La aplicación genera URLs absolutas (como las utilizadas en los correos electrónicos de restablecimiento de contraseña) utilizando el encabezado Host proporcionado por el usuario. Esto permite a atacantes remotos envenenar el enlace de restablecimiento de contraseña enviado a una víctima.
CPE cpe:2.3:a:monicahq:monica:4.1.2:*:*:*:*:*:*:*
References () https://github.com/hungnqdz/cve-research/blob/main/CVE-2026-26747.md - () https://github.com/hungnqdz/cve-research/blob/main/CVE-2026-26747.md - Exploit, Vendor Advisory
References () https://github.com/monicahq/monica - () https://github.com/monicahq/monica - Product

23 Feb 2026, 21:19

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 9.1
CWE CWE-644

20 Feb 2026, 17:25

Type Values Removed Values Added
New CVE
Information

Published : 2026-02-20 17:25

Updated : 2026-02-26 02:42

NVD link : CVE-2026-26747

Mitre link : CVE-2026-26747

CVE.ORG link : CVE-2026-26747

JSON object : View

Products Affected

monicahq

  • monica
CWE
CWE-644

Improper Neutralization of HTTP Headers for Scripting Syntax