diff --git a/pkg/models/project_permissions.go b/pkg/models/project_permissions.go
index 213c9559f..ea22983af 100644
--- a/pkg/models/project_permissions.go
+++ b/pkg/models/project_permissions.go
@@ -250,7 +250,6 @@ func checkPermissionsForProjects(s *xorm.Session, u *user.User, projectIDs []int
 		u.ID,
 		u.ID,
 		u.ID,
-		u.ID,
 	}
 
 	err = s.SQL(`
@@ -274,12 +273,21 @@ WITH RECURSIVE
         FROM projects p
                  INNER JOIN project_hierarchy ph ON p.id = ph.parent_project_id),
 
+    -- Calculate max team permission for each project/user combination
+    max_team_permissions AS (
+        SELECT tl.project_id,
+               MAX(tl.permission) AS max_team_permission
+        FROM team_projects tl
+                 INNER JOIN team_members tm ON tm.team_id = tl.team_id AND tm.user_id = ?
+        GROUP BY tl.project_id
+    ),
+
     project_permissions AS (SELECT ph.id,
                                    ph.original_project_id,
                                    CASE
                                        WHEN p.owner_id = ? THEN 2
-                                       WHEN COALESCE(ul.permission, 0) > COALESCE(tl.permission, 0) THEN ul.permission
-                                       ELSE COALESCE(tl.permission, 0)
+                                       WHEN COALESCE(ul.permission, 0) > COALESCE(mtp.max_team_permission, 0) THEN ul.permission
+                                       ELSE COALESCE(mtp.max_team_permission, 0)
                                        END AS project_permission,
             CASE
                 WHEN p.owner_id = ? THEN 1  -- Direct project ownership
@@ -289,9 +297,8 @@ WITH RECURSIVE
                                 LEFT JOIN projects p
                             ON ph.id = p.id
                                 LEFT JOIN users_projects ul ON ul.project_id = ph.id AND ul.user_id = ?
-                                LEFT JOIN team_projects tl ON tl.project_id = ph.id
-                                LEFT JOIN team_members tm ON tm.team_id = tl.team_id AND tm.user_id = ?
-                            WHERE p.owner_id = ? OR ul.user_id = ? OR tm.user_id = ?)
+                                LEFT JOIN max_team_permissions mtp ON mtp.project_id = ph.id
+                            WHERE p.owner_id = ? OR ul.user_id = ? OR mtp.max_team_permission IS NOT NULL)
 
 SELECT ph.original_project_id AS id,
        COALESCE(MAX(pp.project_permission), -1) AS max_permission
diff --git a/pkg/models/project_permissions_multiple_teams_test.go b/pkg/models/project_permissions_multiple_teams_test.go
new file mode 100644
index 000000000..04efaaeeb
--- /dev/null
+++ b/pkg/models/project_permissions_multiple_teams_test.go
@@ -0,0 +1,702 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package models
+
+import (
+	"testing"
+
+	"code.vikunja.io/api/pkg/db"
+	"code.vikunja.io/api/pkg/user"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"xorm.io/xorm"
+)
+
+// TestProjectPermissions_OwnerInMultipleTeamsWithDifferentPermissions tests the scenario where:
+// - User A creates a project (becomes owner)
+// - User A is part of two teams Y and Z
+// - Project is shared with team Y with admin permissions
+// - Project is shared with team Z with read-only permissions
+// - User A should still have owner/admin permissions (highest permission should apply)
+func TestProjectPermissions_OwnerInMultipleTeamsWithDifferentPermissions(t *testing.T) {
+	// Setup: Load fixtures and create a database session
+	db.LoadAndAssertFixtures(t)
+	s := db.NewSession()
+	defer s.Close()
+
+	// User A (we'll use user 1 from fixtures - needs Username for GetFromAuth)
+	userA := &user.User{
+		ID:       1,
+		Username: "user1",
+	}
+
+	// Create a new project owned by User A
+	project := &Project{
+		Title:       "Test Project for Multiple Teams",
+		Description: "Testing permissions when owner is in multiple teams",
+	}
+	err := project.Create(s, userA)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Verify User A has admin permissions as the owner
+	t.Run("owner has admin permissions before sharing", func(t *testing.T) {
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userA)
+		require.NoError(t, err)
+		assert.True(t, canRead, "Owner should be able to read their project")
+		assert.Equal(t, int(PermissionAdmin), maxPerm, "Owner should have admin permission")
+
+		canWrite, err := project.CanWrite(s, userA)
+		require.NoError(t, err)
+		assert.True(t, canWrite, "Owner should be able to write to their project")
+
+		isAdmin, err := project.IsAdmin(s, userA)
+		require.NoError(t, err)
+		assert.True(t, isAdmin, "Owner should be admin of their project")
+	})
+
+	prepareSharingY := func(sess *xorm.Session) {
+		// Create Team Y - User A will be automatically added as a member when creating the team
+		teamY := &Team{
+			Name:        "Team Y",
+			Description: "Team with admin permissions",
+		}
+		err = teamY.Create(sess, userA)
+		require.NoError(t, err)
+		require.NoError(t, sess.Commit())
+
+		// Share project with Team Y (admin permissions)
+		teamProjectY := &TeamProject{
+			TeamID:     teamY.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionAdmin,
+		}
+		err = teamProjectY.Create(sess, userA)
+		require.NoError(t, err)
+		require.NoError(t, sess.Commit())
+	}
+
+	// Setup sharing with Team Y
+	s = db.NewSession()
+	prepareSharingY(s)
+	s.Close()
+
+	// Verify User A still has admin permissions after sharing with Team Y
+	t.Run("owner has admin permissions after sharing with team Y (admin)", func(t *testing.T) {
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userA)
+		require.NoError(t, err)
+		assert.True(t, canRead, "Owner should be able to read their project after sharing with Team Y")
+		assert.Equal(t, int(PermissionAdmin), maxPerm, "Owner should still have admin permission after sharing with Team Y")
+
+		canWrite, err := project.CanWrite(s, userA)
+		require.NoError(t, err)
+		assert.True(t, canWrite, "Owner should be able to write to their project after sharing with Team Y")
+
+		isAdmin, err := project.IsAdmin(s, userA)
+		require.NoError(t, err)
+		assert.True(t, isAdmin, "Owner should still be admin after sharing with Team Y")
+	})
+
+	prepareTeamSharedMultiple := func(sess *xorm.Session) {
+		// Create Team Z - User A will be automatically added as a member when creating the team
+		teamZ := &Team{
+			Name:        "Team Z",
+			Description: "Team with read-only permissions",
+		}
+		err = teamZ.Create(sess, userA)
+		require.NoError(t, err)
+		require.NoError(t, sess.Commit())
+
+		// Share project with Team Z (read-only permissions)
+		teamProjectZ := &TeamProject{
+			TeamID:     teamZ.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionRead,
+		}
+		err = teamProjectZ.Create(sess, userA)
+		require.NoError(t, err)
+		require.NoError(t, sess.Commit())
+	}
+
+	// Setup sharing with Team Z
+	s = db.NewSession()
+	prepareTeamSharedMultiple(s)
+	s.Close()
+
+	// Verify User A STILL has admin permissions after sharing with Team Z
+	// user should retain highest permission (owner/admin), not be downgraded to read-only
+	t.Run("owner has admin permissions after sharing with team Z (read-only)", func(t *testing.T) {
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userA)
+		require.NoError(t, err)
+		assert.True(t, canRead, "Owner should be able to read their project after sharing with Team Z")
+		assert.Equal(t, int(PermissionAdmin), maxPerm, "Owner should STILL have admin permission (not downgraded to read-only)")
+
+		canWrite, err := project.CanWrite(s, userA)
+		require.NoError(t, err)
+		assert.True(t, canWrite, "Owner should STILL be able to write to their project (not downgraded to read-only)")
+
+		isAdmin, err := project.IsAdmin(s, userA)
+		require.NoError(t, err)
+		assert.True(t, isAdmin, "Owner should STILL be admin (not downgraded to read-only)")
+	})
+}
+
+// TestProjectPermissions_OwnerInMultipleTeamsAdminThenWrite tests the variant where:
+// - User A creates a project
+// - Project is shared with team Y with admin permissions
+// - Project is shared with team Z with write permissions
+// - User A should still have admin permissions (not downgraded to write)
+func TestProjectPermissions_OwnerInMultipleTeamsAdminThenWrite(t *testing.T) {
+	db.LoadAndAssertFixtures(t)
+	s := db.NewSession()
+	defer s.Close()
+
+	userA := &user.User{
+		ID:       1,
+		Username: "user1",
+	}
+
+	// Create a new project owned by User A
+	project := &Project{
+		Title:       "Test Project Admin Then Write",
+		Description: "Testing permissions when owner is in teams with admin then write",
+	}
+	err := project.Create(s, userA)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Create Team Y with admin permissions - User A will be automatically added as a member
+	teamY := &Team{
+		Name: "Team Y Admin",
+	}
+	err = teamY.Create(s, userA)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	teamProjectY := &TeamProject{
+		TeamID:     teamY.ID,
+		ProjectID:  project.ID,
+		Permission: PermissionAdmin,
+	}
+	err = teamProjectY.Create(s, userA)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Create Team Z with write permissions - User A will be automatically added as a member
+	teamZ := &Team{
+		Name: "Team Z Write",
+	}
+	err = teamZ.Create(s, userA)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	teamProjectZ := &TeamProject{
+		TeamID:     teamZ.ID,
+		ProjectID:  project.ID,
+		Permission: PermissionWrite,
+	}
+	err = teamProjectZ.Create(s, userA)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Test: User A should still have admin permissions (not downgraded to write)
+	t.Run("owner has admin permissions after sharing with admin team then write team", func(t *testing.T) {
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userA)
+		require.NoError(t, err)
+		assert.True(t, canRead)
+		assert.Equal(t, int(PermissionAdmin), maxPerm, "Owner should have admin permission, not downgraded to write")
+
+		isAdmin, err := project.IsAdmin(s, userA)
+		require.NoError(t, err)
+		assert.True(t, isAdmin, "Owner should still be admin, not downgraded to write")
+	})
+}
+
+// TestProjectPermissions_NonOwnerInMultipleTeams tests the scenario where:
+// - User B (not the owner) is part of two teams
+// - Team Y has admin permissions on a project
+// - Team Z has read-only permissions on the same project
+// - User B should have admin permissions (highest of the two)
+func TestProjectPermissions_NonOwnerInMultipleTeams(t *testing.T) {
+	db.LoadAndAssertFixtures(t)
+	s := db.NewSession()
+	defer s.Close()
+
+	// User 1 is the owner
+	owner := &user.User{
+		ID:       1,
+		Username: "user1",
+	}
+	// User 2 will be in multiple teams
+	userB := &user.User{
+		ID:       2,
+		Username: "user2",
+	}
+
+	// Create a new project owned by User 1
+	project := &Project{
+		Title:       "Test Project Non-Owner Multiple Teams",
+		Description: "Testing permissions for non-owner in multiple teams",
+	}
+	err := project.Create(s, owner)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Create Team Y with admin permissions
+	teamY := &Team{
+		Name: "Team Y Admin for Non-Owner",
+	}
+	err = teamY.Create(s, owner)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Add User B to Team Y
+	teamMemberY := &TeamMember{
+		TeamID:   teamY.ID,
+		Username: "user2",
+	}
+	err = teamMemberY.Create(s, owner)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Share project with Team Y (admin)
+	teamProjectY := &TeamProject{
+		TeamID:     teamY.ID,
+		ProjectID:  project.ID,
+		Permission: PermissionAdmin,
+	}
+	err = teamProjectY.Create(s, owner)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Verify User B has admin permissions through Team Y
+	t.Run("non-owner has admin through team Y", func(t *testing.T) {
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userB)
+		require.NoError(t, err)
+		assert.True(t, canRead)
+		assert.Equal(t, int(PermissionAdmin), maxPerm)
+
+		isAdmin, err := project.IsAdmin(s, userB)
+		require.NoError(t, err)
+		assert.True(t, isAdmin)
+	})
+
+	// Create Team Z with read-only permissions
+	teamZ := &Team{
+		Name: "Team Z Read for Non-Owner",
+	}
+	err = teamZ.Create(s, owner)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Add User B to Team Z
+	teamMemberZ := &TeamMember{
+		TeamID:   teamZ.ID,
+		Username: "user2",
+	}
+	err = teamMemberZ.Create(s, owner)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Share project with Team Z (read-only)
+	teamProjectZ := &TeamProject{
+		TeamID:     teamZ.ID,
+		ProjectID:  project.ID,
+		Permission: PermissionRead,
+	}
+	err = teamProjectZ.Create(s, owner)
+	require.NoError(t, err)
+	err = s.Commit()
+	require.NoError(t, err)
+
+	// Test: User B should still have admin permissions (highest of Team Y and Team Z)
+	t.Run("non-owner retains admin after adding to read-only team Z", func(t *testing.T) {
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userB)
+		require.NoError(t, err)
+		assert.True(t, canRead)
+		assert.Equal(t, int(PermissionAdmin), maxPerm, "Non-owner should have admin (highest permission), not downgraded to read")
+
+		isAdmin, err := project.IsAdmin(s, userB)
+		require.NoError(t, err)
+		assert.True(t, isAdmin, "Non-owner should still have admin permission, not downgraded to read")
+	})
+}
+
+// TestProjectPermissions_OrderOfSharingDoesNotMatter tests that the order in which
+// teams are granted access doesn't affect the final permission level
+func TestProjectPermissions_OrderOfSharingDoesNotMatter(t *testing.T) {
+	db.LoadAndAssertFixtures(t)
+
+	owner := &user.User{
+		ID:       1,
+		Username: "user1",
+	}
+	userB := &user.User{
+		ID:       2,
+		Username: "user2",
+	}
+
+	// Test 1: Share read-only first, then admin
+	t.Run("share read-only first then admin", func(t *testing.T) {
+		s := db.NewSession()
+		defer s.Close()
+
+		project := &Project{
+			Title: "Test Order: Read then Admin",
+		}
+		err := project.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Create and share with read-only team first
+		teamRead := &Team{Name: "Read First Team"}
+		err = teamRead.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamMemberRead := &TeamMember{TeamID: teamRead.ID, Username: "user2"}
+		err = teamMemberRead.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamProjectRead := &TeamProject{
+			TeamID:     teamRead.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionRead,
+		}
+		err = teamProjectRead.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Now share with admin team
+		teamAdmin := &Team{Name: "Admin Second Team"}
+		err = teamAdmin.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamMemberAdmin := &TeamMember{TeamID: teamAdmin.ID, Username: "user2"}
+		err = teamMemberAdmin.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamProjectAdmin := &TeamProject{
+			TeamID:     teamAdmin.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionAdmin,
+		}
+		err = teamProjectAdmin.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Verify user has admin permission
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userB)
+		require.NoError(t, err)
+		assert.True(t, canRead)
+		assert.Equal(t, int(PermissionAdmin), maxPerm, "User should have admin even though read-only was shared first")
+
+		isAdmin, err := project.IsAdmin(s, userB)
+		require.NoError(t, err)
+		assert.True(t, isAdmin)
+	})
+
+	// Test 2: Share admin first, then read-only (the reported bug scenario)
+	t.Run("share admin first then read-only - REPORTED BUG", func(t *testing.T) {
+		s := db.NewSession()
+		defer s.Close()
+
+		project := &Project{
+			Title: "Test Order: Admin then Read",
+		}
+		err := project.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Create and share with admin team first
+		teamAdmin := &Team{Name: "Admin First Team"}
+		err = teamAdmin.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamMemberAdmin := &TeamMember{TeamID: teamAdmin.ID, Username: "user2"}
+		err = teamMemberAdmin.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamProjectAdmin := &TeamProject{
+			TeamID:     teamAdmin.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionAdmin,
+		}
+		err = teamProjectAdmin.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Now share with read-only team
+		teamRead := &Team{Name: "Read Second Team"}
+		err = teamRead.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamMemberRead := &TeamMember{TeamID: teamRead.ID, Username: "user2"}
+		err = teamMemberRead.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamProjectRead := &TeamProject{
+			TeamID:     teamRead.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionRead,
+		}
+		err = teamProjectRead.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Verify user STILL has admin permission (not downgraded to read)
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userB)
+		require.NoError(t, err)
+		assert.True(t, canRead)
+		assert.Equal(t, int(PermissionAdmin), maxPerm, "User should STILL have admin even though read-only was shared last")
+
+		isAdmin, err := project.IsAdmin(s, userB)
+		require.NoError(t, err)
+		assert.True(t, isAdmin, "User should STILL be admin even though read-only was shared last")
+	})
+}
+
+// TestProjectPermissions_UserInMultipleTeamsWithSamePermission tests the edge case where:
+// - A user belongs to multiple teams that all grant the same permission level
+// - The effective permission should equal that permission level (not more, not less)
+// - This verifies the MAX function works correctly when all permissions are equal
+func TestProjectPermissions_UserInMultipleTeamsWithSamePermission(t *testing.T) {
+	db.LoadAndAssertFixtures(t)
+
+	owner := &user.User{
+		ID:       1,
+		Username: "user1",
+	}
+	userB := &user.User{
+		ID:       2,
+		Username: "user2",
+	}
+
+	// Test: User in two teams, both with read-only permission
+	t.Run("user in multiple teams with same read-only permission", func(t *testing.T) {
+		s := db.NewSession()
+		defer s.Close()
+
+		// Create project
+		project := &Project{
+			Title: "Test Multiple Teams Same Permission",
+		}
+		err := project.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Create first team with read-only permission
+		team1 := &Team{Name: "Team 1 Read"}
+		err = team1.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamMember1 := &TeamMember{TeamID: team1.ID, Username: "user2"}
+		err = teamMember1.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamProject1 := &TeamProject{
+			TeamID:     team1.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionRead,
+		}
+		err = teamProject1.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Create second team with read-only permission
+		team2 := &Team{Name: "Team 2 Read"}
+		err = team2.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamMember2 := &TeamMember{TeamID: team2.ID, Username: "user2"}
+		err = teamMember2.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamProject2 := &TeamProject{
+			TeamID:     team2.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionRead,
+		}
+		err = teamProject2.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Verify user has read permission (not more, not less)
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userB)
+		require.NoError(t, err)
+		assert.True(t, canRead, "User should be able to read")
+		assert.Equal(t, int(PermissionRead), maxPerm, "User should have exactly read permission when all teams grant read-only")
+
+		canWrite, err := project.CanWrite(s, userB)
+		require.NoError(t, err)
+		assert.False(t, canWrite, "User should NOT be able to write with only read permissions")
+
+		isAdmin, err := project.IsAdmin(s, userB)
+		require.NoError(t, err)
+		assert.False(t, isAdmin, "User should NOT be admin with only read permissions")
+	})
+
+	// Test: User in two teams, both with write permission
+	t.Run("user in multiple teams with same write permission", func(t *testing.T) {
+		s := db.NewSession()
+		defer s.Close()
+
+		// Create project
+		project := &Project{
+			Title: "Test Multiple Teams Same Write Permission",
+		}
+		err := project.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Create first team with write permission
+		team1 := &Team{Name: "Team 1 Write"}
+		err = team1.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamMember1 := &TeamMember{TeamID: team1.ID, Username: "user2"}
+		err = teamMember1.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamProject1 := &TeamProject{
+			TeamID:     team1.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionWrite,
+		}
+		err = teamProject1.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Create second team with write permission
+		team2 := &Team{Name: "Team 2 Write"}
+		err = team2.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamMember2 := &TeamMember{TeamID: team2.ID, Username: "user2"}
+		err = teamMember2.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		teamProject2 := &TeamProject{
+			TeamID:     team2.ID,
+			ProjectID:  project.ID,
+			Permission: PermissionWrite,
+		}
+		err = teamProject2.Create(s, owner)
+		require.NoError(t, err)
+		err = s.Commit()
+		require.NoError(t, err)
+
+		// Verify user has write permission
+		s = db.NewSession()
+		defer s.Close()
+
+		canRead, maxPerm, err := project.CanRead(s, userB)
+		require.NoError(t, err)
+		assert.True(t, canRead, "User should be able to read")
+		assert.Equal(t, int(PermissionWrite), maxPerm, "User should have exactly write permission when all teams grant write")
+
+		canWrite, err := project.CanWrite(s, userB)
+		require.NoError(t, err)
+		assert.True(t, canWrite, "User should be able to write")
+
+		isAdmin, err := project.IsAdmin(s, userB)
+		require.NoError(t, err)
+		assert.False(t, isAdmin, "User should NOT be admin with only write permissions")
+	})
+}