Submitted by Bigsam, also found by attentioniayn, Benterkiii, farismaulana, foufrix, hubble, knight18695, and spuriousdragon
https://github.com/code-423n4/2024-12-secondswap/blob/214849c3517eb26b31fe194bceae65cb0f52d2c0/contracts/SecondSwap_VestingManager.sol#L167-L186
https://github.com/code-423n4/2024-12-secondswap/blob/214849c3517eb26b31fe194bceae65cb0f52d2c0/contracts/SecondSwap_VestingManager.sol#L161-L164
A token marked sellable can be purchased because of the absence of the sellable check when completing a spot purchase.
A user is not permitted to vest tokens that are not marked as sellable by the contract and admin
But these tokens are always marked as sellable on deployment and admin has the Power to mark them as unsellable
On deployment it is always set to true 
After a user lists this token and admin makes this token unsellable, a user can still purchase this token successfully 1 second after it has been marked unsellable because of a missing check in the complete purchase function.
Add a sellable check in the completePurchase function has done in the listVesting function
TechticalRAM (SecondSwap) confirmed
