CVE-2026-73257: CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in cesanta mongoose
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.
CVE-2026-73257: CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in cesanta mongoose
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.
CVSS v3.1
Score 9.1critical
Weaknesses
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-11T17:18:01.598Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a873eeeacd9273b49f2b5e8
Added to database: 08/20/2026, 17:52:46 UTC
Last updated: 08/20/2026, 17:52:46 UTC
Views: 1
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