cvedb.io
CVE-2026-23829
MEDIUM · CVSS 5.3
EPSS exploitation probability: 0%
Published 2026-01-19T00:15:48.707 · Last modified 2026-06-17T10:22:10.143

Summary

Mailpit is an email testing tool and API for developers. Prior to version 1.28.3, Mailpit's SMTP server is vulnerable to Header Injection due to an insufficient Regular Expression used to validate `RCPT TO` and `MAIL FROM` addresses. An attacker can inject arbitrary SMTP headers (or corrupt existing ones) by including carriage return characters (`\r`) in the email address. This header injection occurs because the regex intended to filter control characters fails to exclude `\r` and `\n` when used inside a character class. Version 1.28.3 fixes this issue.

Affected products

axllent — mailpit

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.