CVE-2026-55612

uhttpd is a small HTTP server. In unpatched repository snapshots, client_poll_post_data() in client.c consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears r->content_length and r->transfer_chunked without draining the remaining body or setting request.connection_close. The completion check treats the chunked POST as finished and the keep-alive parser returns to CLIENT_STATE_INIT. Attacker-controlled body bytes aligned as a complete HTTP request are then parsed and processed as another request on the same connection, causing HTTP request smuggling and request-boundary desynchronization. Commits b78f518478794e16ba3568fc1258e40bf3e8eb3b and 34460b8211d676ef1b9f40d6b775c5e112933690 patch the issue.

uhttpd is a small HTTP server. In unpatched repository snapshots, client_poll_post_data() in client.c consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears r->content_length and r->transfer_chunked without draining the remaining body or setting request.connection_close. The completion check treats the chunked POST as finished and the keep-alive parser returns to CLIENT_STATE_INIT. Attacker-controlled body bytes aligned as a complete HTTP request are then parsed and processed as another request on the same connection, causing HTTP request smuggling and request-boundary desynchronization. Commits b78f518478794e16ba3568fc1258e40bf3e8eb3b and 34460b8211d676ef1b9f40d6b775c5e112933690 patch the issue.

uhttpd is a small HTTP server. In unpatched repository snapshots, client_poll_post_data() in client.c consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears r->content_length and r->transfer_chunked without draining the remaining body or setting request.connection_close. The completion check treats the chunked POST as finished and the keep-alive parser returns to CLIENT_STATE_INIT. Attacker-controlled body bytes aligned as a complete HTTP request are then parsed and processed as another request on the same connection, causing HTTP request smuggling and request-boundary desynchronization. Commits b78f518478794e16ba3568fc1258e40bf3e8eb3b and 34460b8211d676ef1b9f40d6b775c5e112933690 patch the issue.

uhttpd is a small HTTP server. In unpatched repository snapshots, client_poll_post_data() in client.c consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears r->content_length and r->transfer_chunked without draining the remaining body or setting request.connection_close. The completion check treats the chunked POST as finished and the keep-alive parser returns to CLIENT_STATE_INIT. Attacker-controlled body bytes aligned as a complete HTTP request are then parsed and processed as another request on the same connection, causing HTTP request smuggling and request-boundary desynchronization. Commits b78f518478794e16ba3568fc1258e40bf3e8eb3b and 34460b8211d676ef1b9f40d6b775c5e112933690 patch the issue.