Vulnerability · Published Jul 20, 2026 · Assigned by GitHub_M
CVE-2026-45711Mailpit: Path traversal & arbitrary file write in mailpit dump --http via attacker-controlled message IDs
Medium 5.9
In plain English
A medium-severity path traversal in mailpit from axllent. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/axllent/mailpit | 1.30.0 | GHSA-qx5x-85p8-vg4j |
| Go | github.com/axllent/mailpit | 1.30.0 | GO-2026-5599 |
Affected products (as reported)
Weakness: CWE-22, CWE-829 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:L
References
- https://github.com/axllent/mailpit/security/advisories/GHSA-qx5x-85p8-vg4j x_refsource_CONFIRM
- https://github.com/axllent/mailpit/releases/tag/v1.30.0 x_refsource_MISC