As JPMorgan Chase & Co. hammers out a $13 billion settlement with the government, the bank has more to worry about than paying Uncle Sam and consumers. Any settlement would also have direct repercussions in a $10 billion lawsuit Deutsche Bank National Trust Co. has filed over shoddy assets.

For JPMorgan, one challenge is to finesse a deal with the feds without assuming liability in the Deutsche Bank suit, pending in U.S. District Court for the District of Columbia.