git-shell in git before 2.4.12, 2.5.x before 2.5.6, 2.6.x before 2.6.7, 2.7.x before 2.7.5, 2.8.x before 2.8.5, 2.9.x before 2.9.4, 2.10.x before 2.10.3, 2.11.x before 2.11.2, and 2.12.x before 2.12.3 might allow remote authenticated users to gain privileges via a repository name that starts with a - (dash) character.