Pony MailApplication · Apache
CVE-2026-41873
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · unedited** 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceHTTP Request Smuggling vulnerability in the Lua implementation of Pony Mail allows attackers to manipulate HTTP requests in a way that can bypass authentication controls and lead to admin account takeover. The vulnerability exploits inconsistencies in how the server parses HTTP requests, potentially allowing session hijacking or privilege escalation.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Pony MailApplication
all versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm Pony Mail installationSearch for Pony Mail files in common locations such as /usr/local/ponymail, /opt/ponymail, or check for a 'ponymail' service running on typical ports (8080, 80). Look for files named 'ponymail.lua' or directories containing 'lua' implementation files.Affected if Pony Mail is installed and running with the Lua HTTP handler enabled.
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Identify Lua HTTP handler in useExamine the Pony Mail configuration file (typically archConfig.lua or config.lua) for settings related to HTTP handling. Look for entries that specify 'lua', 'lua-http', or similar Lua-based request processing modules.Affected if The configuration explicitly uses a Lua-based HTTP implementation for request parsing.
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Check HTTP request parsing configurationReview the Lua HTTP handler code or configuration for how it parses HTTP headers, particularly Transfer-Encoding and Content-Length headers. Look for inconsistencies in header processing between different request stages.Affected if The Lua HTTP handler processes Transfer-Encoding and Content-Length headers in a way that allows conflicting values to coexist.
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Test for request smuggling behaviorSend HTTP requests with both Transfer-Encoding: chunked and Content-Length headers with mismatched values to the Pony Mail server. Observe if the server processes them differently than a standards-compliant parser would.Affected if The server accepts and processes requests with conflicting Transfer-Encoding and Content-Length headers without rejecting the ambiguous request.
A user is affected if they are running any version of Apache Pony Mail with the Lua HTTP implementation enabled, as all versions contain the request smuggling vulnerability.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedSince no patch is available (retired product), organizations should either restrict network access to trusted users only or migrate to an alternative solution. Implement strict network-level access controls and consider implementing additional authentication layers if continued use is unavoidable.
- Restrict network access to the Pony Mail instance to trusted users only, for example via firewall rules, IP allowlisting, or VPN authentication.
- Evaluate migrating to an alternative mail archiving solution, as the Lua implementation is retired and will not receive security updates.
- If continued use is unavoidable, implement additional monitoring and intrusion detection to mitigate potential exploitation of this HTTP Request Smuggling vulnerability.
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Pony Mail
Scoped from the published advisory
- Consultation6.0 h
- Implementation12.0 h
- Testing4.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-41873 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-41873 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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