CVE-2026-45711: Axllent Mailpit

High severity, CVSS 8.2. EPSS: 0.4% chance of exploitation in the next 30 days.

Mailpit is an email testing tool and API for developers. Prior to version 1.30.0, the mailpit dump --http <base-url> <out-dir> sub-command downloads every message from a remote Mailpit instance and writes each one as <id>.eml inside the user-supplied output directory. The message ID field is taken verbatim from the JSON response of the remote server and concatenated into the output path with path.Join, which silently normalizes `..` segments. A malicious HTTP server impersonating Mailpit can therefore make mailpit dump write attacker-controlled bytes to any path the running user can write, fully outside the intended output directory. Version 1.30.0 contains a patch.

Affected products

• Axllent Mailpit: before 1.30.0 (fixed in 1.30.0)

Published 2026-07-20. Last modified 2026-07-28.