Clear the buffer data before sprinting to it.
diff --git a/cgminer.c b/cgminer.c
index b5f82cb..49f9c4f 100644
--- a/cgminer.c
+++ b/cgminer.c
@@ -2772,6 +2772,7 @@ static void *submit_work_thread(void *userdata)
nonce = *((uint32_t *)(work->data + 76));
noncehex = bin2hex((const unsigned char *)&nonce, 4);
+ memset(s, 0, 1024);
sprintf(s, "{\"params\": [\"%s\", \"%s\", \"%s\", \"%s\", \"%s\"], \"id\": %d, \"method\": \"mining.submit\"}",
pool->rpc_user, work->job_id, work->nonce2, work->ntime, noncehex, sshare->id);
free(noncehex);