Werder Bremen have extended their contract with Weiser, the club confirmed on their website, though the length of the new deal has not been disclosed.
The extension comes after a lost season for the versatile 32-year-old, who suffered a serious knee injury in pre-season training last July and missed the entirety of the campaign as a result.
Weiser is now nearing full fitness again, a development that has delighted head coach Daniel Thioune as the player commits his future to the club.
"For me, Mitch is almost like a new signing. We hope he returns from his injury in top form," Thioune said. "There's no doubt about the quality he has as a player, and he'll be a huge asset for our team."
Weiser, who can play at full-back or on the wing, has been with Werder Bremen since 2022 and has made 123 appearances for the club.
Keeping hold of Weiser through his recovery represents a vote of confidence from Bremen's hierarchy in a player who had established himself as a key contributor before the injury disrupted his season entirely, with the club clearly viewing his return to fitness as a meaningful boost heading into next season rather than a player whose best years are necessarily behind him.
Weiser came through Cologne's academy before spells at Bayern Munich and Hertha Berlin, and has previously spoken of his ambition to represent Algeria at international level, having become eligible through his maternal grandfather.
A full recovery from this latest setback would also revive those international prospects, which had gathered momentum before his injury halted his season before it had even begun.