CVE-2026-41873: Pony Mail: Admin account takeover via request smuggling

[Arnout Engelen <engelen () apache org>]

Severity: critical 

Affected versions:

- Pony Mail: all versions

Description:

** UNSUPPORTED WHEN ASSIGNED ** Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') 
vulnerability in Pony Mail leading to admin account takeover.

This issue affects all versions of the Lua implementation of Pony Mail. There is a Python implementation under 
development under the name "Pony Mail Foal" that is not affected by this issue, but hasn't been released yet.

As the Lua implementation of this project is retired, we do not plan to release a version that fixes this issue. Users 
are recommended to find an alternative or restrict access to the instance to trusted users.

NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

Credit:

Li Jiantao (@CurseRed) of STAR Labs SG Pte. Ltd. (@starlabs_sg) (finder)
Tevel Sho of STAR Labs SG Pte. Ltd (finder)

References:

https://ponymail.apache.org
https://www.cve.org/CVERecord?id=CVE-2026-41873