The release issued by RJD general secretary SM Qamar Alam said the appointments were made by Lalu Yadav.
Lalu Yadav's three children--Tej Pratap Yadav, Tejashwi Yadav and Misa Bharti--have also made it to the panel.
Mr Jethmalani is an RJD member of the Rajya Sabha from Bihar.
Though Shahabuddin has been dropped, his wife Heena Shahab has found a place in the executive.
Shahabuddin, a four-time former MP from Siwan, has over three dozen criminal cases against him, and is lodged in Delhi's Tihar jail.
Lalu Yadav was re-elected as party president in November last year, and his tenure would end in 2020. His wife Rabri Devi, a former chief minister, has been named vice president alongside party veterans Raghuvansh Prasad Singh, Mangni Lal Mandal, Mohammad Iliyas Hussain and Shivanand Tiwari.
JD(U) spokesman and MLC Sanjay Singh took a dig at Lalu Yadav over nominating the party executive from behind the bars.
"In the history of Indian democracy, this is the first example of a party's national president constituting its national executive from jail," he said.
Lalu Yadav is lodged in a Ranchi jail since December 23 last when he was convicted in a fodder scam case. Within days, he was convicted in another case.
"The new national executive has established that RJD belongs to one family.....it would be better if the party is named after Lalu Prasad and his sons-in-law too are inducted into the national executive," Mr Singh said.
"Lalu is running the party from jail. He should have also included in the national executive Raj Ballabh Yadav," Mr Singh said referring to a suspended RJD MLA who is in jail in a rape case.
Another JD(U) spokesman Neeraj Kumar accused the RJD chief of adopting "double standards" by dropping Shahabuddin from the national executive but retaining his own position.
"When law enforcing agencies were acting against Shahabuddin and Raj Ballabh Yadav, Prasad was singing paeans to these tainted figures. Now he has sidelined these men, retaining the party president's post and securing the position of his sons and daughter in the party," Mr Kumar said.
"Even a senior leader like Abdul Bari Siddiqui has been made to look like an also ran. So much for the RJD leadership's claims of championing secularism and rights of the minorities," Mr Kumar said.