CVE-2026-73257

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.
Configurations

Configuration 1 (hide)

cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:*

History

18 Oct 2026, 20:10

Type Values Removed Values Added
Summary
  • (es) Mongoose es un servidor web incrustado y una biblioteca de red. Antes de la versión 7.22, un atacante remoto no autenticado puede enviar una solicitud HTTP que contenga tanto Content-Length como Transfer-Encoding: chunked. Las comprobaciones cl_count y te_count en las rutas mg_http_parse() y http_cb() en src/http.c aceptan ambos encabezados y priorizan la codificación chunked, mientras que un proxy inverso que prefiere Content-Length puede usar un límite de solicitud diferente. Esta desincronización CL.TE puede inyectar solicitudes que acceden o modifican recursos en otro contexto de usuario. Este problema está solucionado en la versión 7.22.

29 Sep 2026, 15:39

Type Values Removed Values Added
CPE cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:*
First Time Cesanta mongoose
Cesanta
References () https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71 - () https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71 - Patch
References () https://github.com/cesanta/mongoose/pull/3611 - () https://github.com/cesanta/mongoose/pull/3611 - Issue Tracking, Patch
References () https://github.com/cesanta/mongoose/releases/tag/7.22 - () https://github.com/cesanta/mongoose/releases/tag/7.22 - Release Notes
References () https://github.com/cesanta/mongoose/security/advisories/GHSA-5wfq-r6mr-wqp6 - () https://github.com/cesanta/mongoose/security/advisories/GHSA-5wfq-r6mr-wqp6 - Exploit, Vendor Advisory

Information

Published : 2026-08-20 18:16

Updated : 2026-10-18 20:10


NVD link : CVE-2026-73257

Mitre link : CVE-2026-73257

CVE.ORG link : CVE-2026-73257


JSON object : View

Products Affected

cesanta

  • mongoose
CWE
CWE-444

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')