CVE-2026-26747

Host Header Poisoning in Monica 4.1.2 Enables Phished Password Reset Links

Published Feb 20, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
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,

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Host Header Poisoning in Monica 4.1.2 Enables Phished Password Reset Links
Type Values Removed Values Added
CPEs cpe:2.3:a:monicahq:monica:4.1.2:*:*:*:*:*:*:*
Type Values Removed Values Added
Weaknesses CWE-644
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Monicahq
Monicahq monica
Vendors & Products Monicahq
Monicahq monica
Type Values Removed Values Added
Description 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,
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Feb 23, 2026, 8:37 PM
Reserved
Feb 16, 2026, 12:00 AM
Status
Analyzed
Published
Feb 20, 2026, 5:25 PM
Modified
Jun 17, 2026, 10:26 AM