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 (2)
Core 2
Core References
Various Sources
https://github.com/monicahq/monica
Scores
CVSS v3
9.1
EPSS
0.0008
EPSS Percentile
23.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-644
Status
published
Products (1)
monicahq/monica
4.1.2
Published
Feb 20, 2026
Tracked Since
Feb 21, 2026