fix(project): improved access control for project users (backport #56675) (#57180)

Co-authored-by: Diptanil Saha <diptanil@frappe.io>

erpnext/templates/pages/projects.py

@@ -6,21 +6,12 @@ import frappe
 
 
 def get_context(context):
-	project_user = frappe.db.get_value(
-		"Project User",
-		{"parent": frappe.form_dict.project, "user": frappe.session.user},
-		["user", "view_attachments", "hide_timesheets"],
-		as_dict=True,
-	)
-	if frappe.session.user != "Administrator" and (not project_user or frappe.session.user == "Guest"):
-		raise frappe.PermissionError
+	project_user = validate_and_get_project_user(project=frappe.form_dict.project)
 
 	context.no_cache = 1
 	context.show_sidebar = True
 	project = frappe.get_doc("Project", frappe.form_dict.project)
 
-	project.has_permission("read")
-
 	project.tasks = get_tasks(
 		project.name, start=0, item_status="open", search=frappe.form_dict.get("search")
 	)
@@ -66,6 +57,7 @@ def get_tasks(project, start=0, search=None, item_status=None):
 
 @frappe.whitelist()
 def get_task_html(project: str, start: int = 0, item_status: str | None = None):
+	validate_and_get_project_user(project=project)
 	return frappe.render_template(
 		"erpnext/templates/includes/projects/project_tasks.html",
 		{
@@ -106,6 +98,7 @@ def get_timesheets(project, start=0, search=None):
 
 @frappe.whitelist()
 def get_timesheet_html(project: str, start: int = 0):
+	validate_and_get_project_user(project=project)
 	return frappe.render_template(
 		"erpnext/templates/includes/projects/project_timesheets.html",
 		{"doc": {"timesheets": get_timesheets(project, start)}},
@@ -119,3 +112,12 @@ def get_attachments(project):
 		filters={"attached_to_name": project, "attached_to_doctype": "Project", "is_private": 0},
 		fields=["file_name", "file_url", "file_size"],
 	)
+
+
+def validate_and_get_project_user(project: str):
+	project_doc = frappe.get_doc("Project", project)
+	project_doc.check_permission()
+
+	project_user = next((d for d in project_doc.users if d.user == frappe.session.user), None)
+
+	return project_user

erpnext/templates/pages/test_projects.py

@@ -0,0 +1,72 @@
+# Copyright (c) 2026, Frappe Technologies Pvt. Ltd. and Contributors
+# License: GNU General Public License v3. See license.txt
+
+import frappe
+from frappe.tests.utils import FrappeTestCase
+
+from erpnext.projects.doctype.project.test_project import make_project
+from erpnext.templates.pages.projects import validate_and_get_project_user
+
+
+class TestProjectsPage(FrappeTestCase):
+	"""validate_and_get_project_user() gates the /projects portal page. It must raise
+	frappe.PermissionError for a user who can't read the Project, and otherwise return
+	that user's Project User row (or None if they're permitted but not listed as one --
+	e.g. an internal Projects Manager browsing the portal)."""
+
+	def _create_user(self, email):
+		if not frappe.db.exists("User", email):
+			frappe.get_doc(
+				{
+					"doctype": "User",
+					"email": email,
+					"first_name": "Portal",
+					"send_welcome_email": 0,
+				}
+			).insert(ignore_permissions=True)
+		return email
+
+	def test_raises_permission_error_for_user_without_access(self):
+		project = make_project({"project_name": f"_Test Portal Access {frappe.generate_hash(length=6)}"})
+		outsider = self._create_user(f"outsider_{frappe.generate_hash(length=6)}@example.com")
+
+		with self.set_user(outsider):
+			self.assertRaises(frappe.PermissionError, validate_and_get_project_user, project.name)
+
+	def test_allows_user_listed_as_project_user_and_returns_their_row(self):
+		# Being a Project User shares the Project with that user (see
+		# Project.control_access_for_project_users), which is what lets them past
+		# check_permission() here.
+		member = self._create_user(f"member_{frappe.generate_hash(length=6)}@example.com")
+
+		project = frappe.get_doc(
+			doctype="Project",
+			project_name=f"_Test Portal Access {frappe.generate_hash(length=6)}",
+			status="Open",
+			company="_Test Company",
+		)
+		project.append(
+			"users", {"user": member, "view_attachments": 1, "hide_timesheets": 1, "welcome_email_sent": 1}
+		)
+		project.insert()
+
+		with self.set_user(member):
+			project_user = validate_and_get_project_user(project.name)
+
+		self.assertIsNotNone(project_user)
+		self.assertEqual(project_user.user, member)
+		self.assertEqual(project_user.view_attachments, 1)
+		self.assertEqual(project_user.hide_timesheets, 1)
+
+	def test_allows_internally_permitted_user_not_listed_as_project_user(self):
+		# The permission gate must be the real permission system (check_permission()),
+		# not "is this user in the Project's users child table" -- a Projects Manager
+		# can open any project's portal page without ever being added as its user.
+		project = make_project({"project_name": f"_Test Portal Access {frappe.generate_hash(length=6)}"})
+		manager = self._create_user(f"manager_{frappe.generate_hash(length=6)}@example.com")
+		frappe.get_doc("User", manager).add_roles("Projects Manager")
+
+		with self.set_user(manager):
+			project_user = validate_and_get_project_user(project.name)
+
+		self.assertIsNone(project_user)