CVE-2026-102716: An unauthenticated client can drain the RTSP server's packet pool with a couple of dozen requests that carry a Session header the parser

An unauthenticated client can drain the RTSP server's packet pool with a couple of dozen requests that carry a Session header the parser cannot convert. The Session branch returns the raw NetX error code instead of an RTSP status code: ```c /* addons/rtsp/nx_rtsp_server.c:2754 */ status = _nx_utility_string_to_uint(field_value_ptr, field_value_length, &session_id); if (status) { return(status); /* NX_INVALID_PARAMETERS / NX_SIZE_ERROR / NX_OVERFLOW */ } ``` Every other branch of the same function maps its failure to an RTSP status first. The CSeq branch eighteen lines earlier does exactly that (line 2736 returns NX_RTSP_STATUS_CODE_BAD_REQUEST). The raw code then reaches `_nx_rtsp_server_error_response_send` (nx_rtsp_server.c:1234), which does not recognise it, takes a path that returns without releasing the response packet it already allocated, and the block never goes back to the pool. Six requests with an empty Session header against a 22 packet pool: ``` valid requests: after request 6: pool available = 21, AFTER = 22 / 22 malformed requests: after request 6: pool available = 16, AFTER = 17 / 22 ``` One block per request, not returned when the client disconnects. Twenty six requests take the pool to zero and the server starts failing allocations, after which it serves nobody. If the pool is shared with the rest of the application, as it is in the shipped sample, the rest of the stack stops with it. Convert the `_nx_utility_string_to_uint` failure in the Session branch into NX_RTSP_STATUS_CODE_BAD_REQUEST the way the CSeq branch does, and release the response packet on every exit path of `_nx_rtsp_server_error_response_send`.

• Pre-auth
• Denial of service

Published

Sep 29, 2026

Updated

Sep 29, 2026

EPSS

0.2% · 16th percentile

CWE

CWE-401