CVE-2026-73257
Mongoose: Content-Length + Transfer-Encoding coexistence enables request smuggling
- State
- Published
- Severity
- 9.1 Critical
- Published
- Aug 20, 2026
- Updated
- Aug 20, 2026
- Reserved
- Aug 11, 2026
Description
Mongoose is an embedded web server and network library. Priro to version 7.22, a remote unauthenticated attacker can send an HTTP request containing both Content-Length and Transfer-Encoding: chunked. The cl_count and te_count checks in the mg_http_parse() and http_cb() paths in src/http.c accept both headers and prioritize chunked encoding, while a Content-Length-preferring reverse proxy can use a different request boundary. This CL.TE desynchronization can inject requests that access or modify resources in another user context. This issue is fixed in version 7.22.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | GitHub_M |
Weaknesses
- CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Affected Products
| Product | Versions |
|---|---|
mongoosecesanta |
|
References
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