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CVSS v3.1
5.8
EPSS
0.39%
Published
Jan 19, 2026
Modified
Feb 5, 2026
Public PoC / Exploit (1)
All weaponized →Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.
Description
Mailpit is an email testing tool and API for developers. Versions prior to 1.28.3 are vulnerable to Server-Side Request Forgery (SSRF) via HTML Check CSS Download. The HTML Check feature (`/api/v1/message/{ID}/html-check`) is designed to analyze HTML emails for compatibility. During this process, the `inlineRemoteCSS()` function automatically downloads CSS files from external `<link rel="stylesheet" href="...">` tags to inline them for testing. Version 1.28.3 fixes the issue.
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:NWeaknesses (CWE)
Affected Products (1)
References (3)