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.
Scoring
- Severity
- CRITICAL
- CVSS base score
- 9.1
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- EPSS probability
- 0.38%
- CWE
- CWE-444
- Published
- 2026-08-20
- Last modified
- 2026-08-20
Affected products
- cesanta mongoose
Weakness type
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