Admin account takeover via CRLF request smuggling
Published Apr 28, 2026 · Updated Apr 28, 2026
HTTP request smuggling in Apache Pony Mail's Lua implementation allows remote attackers to take over administrator accounts without authentication. The email.lua handler escapes only double quotes in the id parameter before LuaSocket inserts it into a raw Elasticsearch request, so CRLF bytes terminate that request and inject another. A network-reachable legacy instance with its Elasticsearch backend available to the application is sufficient to forge an administrator document and known session cookie.
Summary
What happened
HTTP request smuggling in Apache Pony Mail's Lua implementation allows remote attackers to take over administrator accounts without authentication. The email.lua handler escapes only double quotes in the id parameter before LuaSocket inserts it into a raw Elasticsearch request, so CRLF bytes terminate that request and inject another. A network-reachable legacy instance with its Elasticsearch backend available to the application is sufficient to forge an administrator document and known session cookie.
The record
- CVE
- CVE-2026-41873
- Published
- Apr 28, 2026
- Updated
- Apr 28, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache Pony Mail
- Classifications
- CWE-444, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 28, 2026CVE publishedPublication date reported by the CVE source.
- Apr 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=*
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- STAR Labs CRLF request-smuggling administrator forgery payloadproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo