Addicks boss Chris Powell has been operating with much the same squad which won npower League One last year, and has yet to bring in any new faces since the transfer window reopened.
Charlton currently sit 12th in the Championship after three straight wins, and Valley skipper Jackson says some reinforcements would be welcome to ensure they keep climbing the table.
"A couple of bodies would help, certainly," said the midfielder.
"The gaffer has highlighted some areas in the squad where we might be a bit thin and could do with some reinforcements.
"I think we would all welcome that. We haven't got a massive squad and at this time of year you can pick up injuries and we have had suspensions, so a couple more would help."