9.1
Critical
CVE-2026-73256 Mongoose is an embedded web server and network library
Description
Mongoose is an embedded web server and network library. Prior to 7.22, a remote unauthenticated attacker can exploit an HTTP/1.0 reverse-proxy deployment by sending a request with Transfer-Encoding: chunked and conflicting framing. The http_cb() function in src/http.c tests hm.proto.len with an impossible greater-than-eight condition even though mg_http_parse() requires an eight-byte protocol string, so is_http_1_0 is never set. Mongoose consequently processes chunked encoding that an HTTP/1.0 proxy can ignore, enabling request smuggling and unauthorized access or state changes. This issue is fixed in version 7.22.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Mongoose 7.22 | earliest → < 7.22 | 7.22 |
Other CVEs of Mongoose
The 38 CVEs of Mongoose →
CVE-2026-115473
Mongoose: Heap OOB reads and null-byte bypass in mg_path_is_sane (util.c)
6.5
Medium
CVE-2026-63626
Mongoose is an embedded web server and network library
8.8
High
CVE-2026-73261
Mongoose is an embedded web server and network library
7.5
High
CVE-2026-73260
Mongoose is an embedded web server and network library
7.5
High