Apache Pony Mail HTTP Request request smuggling

Summaryinfo

A vulnerability described as critical has been identified in Apache Pony Mail. Impacted is an unknown function of the component HTTP Request Handler. Executing a manipulation can lead to request smuggling. This vulnerability only affects products that are no longer supported by the maintainer. This vulnerability is registered as CVE-2026-41873. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in Apache Pony Mail (unknown version). It has been declared as critical. This vulnerability affects an unknown code block of the component HTTP Request Handler. The manipulation with an unknown input leads to a request smuggling vulnerability. The CWE definition for the vulnerability is CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

** 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.

The weakness was published by li jiantao. The advisory is shared for download at lists.apache.org. This vulnerability was named CVE-2026-41873 since 04/22/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 04/28/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-26065). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Apache

Name

• Pony Mail

License

• open-source

Support

• end of life

Website

• Vendor: https://www.apache.org/

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Once again VulDB remains the best source for vulnerability data.

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