The 49ers signed veteran cornerback Leon Hall, Adam Schefter of ESPN reported.
San Francisco worked out Hall in May and again last month.
Injuries have hit San Francisco’s secondary hard, and, as a team, the 49ers have only three interceptions.
The Bengals made Hall a first-round pick in 2007. He spent nine years in Cincinnati before signing with the Giants before the start of the 2016 season.
He made 31 tackles, two sacks, an interception, a forced fumble and two pass breakups in 12 games last season.
In 10 seasons, he has 27 interceptions, 114 pass breakups and six forced fumbles.