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,

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

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

No history.

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

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