7.5
High
CVE-2026-73261 Mongoose is an embedded web server and network library
Description
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TCP/IP stack enabled by MG_ENABLE_TCPIP in src/net_builtin.c does not reject a TCP option whose declared opts[1] length exceeds the remaining option bytes. In handle_opt(), a NOP followed by a truncated MSS option causes opts[3] to be read outside the declared options area and used as the low byte of dmss. An unauthenticated remote peer can corrupt the per-connection MSS value so later mg_send() calls transmit truncated or zero-length application payloads while the TCP connection otherwise appears healthy. This issue is fixed in version 7.23.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Mongoose 7.23 | earliest → < 7.23 | 7.23 |
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-2026-73260
Mongoose is an embedded web server and network library
7.5
High
CVE-2026-73252
Mongoose is an embedded web server and network library
7.5
High