https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8
https://bugs.gentoo.org/977961#c11
--- a/src/transport.c	2024-10-16 10:03:21.000000000 +0200
+++ b/src/transport.c	2026-07-07 02:38:20.942968610 +0200
@@ -639,8 +639,12 @@
                 total_num = 4;
 
                 p->packet_length = _libssh2_ntohu32(block);
-                if(p->packet_length < 1)
+                if(p->packet_length < 1) {
                     return LIBSSH2_ERROR_DECRYPT;
+                }
+                else if(p->packet_length > LIBSSH2_PACKET_MAXPAYLOAD) {
+                    return LIBSSH2_ERROR_OUT_OF_BOUNDARY;
+                }
 
                 /* total_num may include size field, however due to existing
                  * logic it needs to be removed after the entire packet is read