CVE-2026-23845 MEDIUM

CVE-2026-23845: Mailpit Vulnerable to Server-Side Request Forgery (SSRF) via HTML Check API

Vendor Axllent
Product mailpit
Weakness CWE-918 · SSRF
Published January 19, 2026
Last update January 20, 2026
View on NVD All CVEs

CVSS base score

5.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

January 19, 2026 CVE published
January 20, 2026 Record updated

Related vulnerabilities

04Related CVE

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