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.
Metrics
Affected Vendors & Products
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Advisories
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Fixes
Solution
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Workaround
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References
History
Mon, 19 Jan 2026 19:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Mailpit Vulnerable to Server-Side Request Forgery (SSRF) via HTML Check API | |
| Weaknesses | CWE-918 | |
| References |
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| Metrics |
cvssV3_1
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Projects
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MITRE
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-01-19T19:01:38.163Z
Reserved: 2026-01-16T15:46:40.842Z
Link: CVE-2026-23845
Vulnrichment
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NVD
Status : Received
Published: 2026-01-19T19:16:04.820
Modified: 2026-01-19T19:16:04.820
Link: CVE-2026-23845
Redhat
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OpenCVE Enrichment
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Weaknesses