Submitted by cccz, also found by Ruhum, catchup, IllIllI, WatchPug, berndartmueller, plotchy, antonttc, hyh, and 0xf15ers
The get function of the INFTOracle interface returns two values, but the success value is not checked when used in the NFTPairWithOracle contract. When success is false, NFTOracle may return stale data.
https://github.com/code-423n4/2022-04-abranft/blob/5cd4edc3298c05748e952f8a8c93e42f930a78c2/contracts/interfaces/INFTOracle.sol#L10-L10 
https://github.com/code-423n4/2022-04-abranft/blob/5cd4edc3298c05748e952f8a8c93e42f930a78c2/contracts/NFTPairWithOracle.sol#L287-L287
https://github.com/code-423n4/2022-04-abranft/blob/5cd4edc3298c05748e952f8a8c93e42f930a78c2/contracts/NFTPairWithOracle.sol#L321-L321
cryptolyndon (AbraNFT) confirmed and commented:
0xean (judge) increased severity to High and commented:
