diff --git a/hub/src/org/explorer.ts b/hub/src/org/explorer.ts
index 784c479..5018a58 100644
--- a/hub/src/org/explorer.ts
+++ b/hub/src/org/explorer.ts
@@ -350,16 +350,17 @@ export async function listMyProjects(
     { feishuOpenId: input.actorFeishuOpenId },
     { organizationId: input.organizationId },
   );
-  const principalKeys = resolution.principals.map((p) => `${p.type}:${p.id}`);
-  if (principalKeys.length === 0) return [];
-  const principalTypes = resolution.principals.map((p) => p.type);
-  const principalIds = resolution.principals.map((p) => p.id);
+  // Match exact (type, id) pairs — independent IN filters form a cartesian
+  // product and can attribute another principal's grants to this actor.
+  if (resolution.principals.length === 0) return [];
   const grants = await prisma.permissionGrant.findMany({
     where: {
       resourceType: "PROJECT",
       revokedAt: null,
-      principalType: { in: principalTypes },
-      principalId: { in: principalIds },
+      OR: resolution.principals.map((p) => ({
+        principalType: p.type,
+        principalId: p.id,
+      })),
     },
     select: { resourceId: true },
     distinct: ["resourceId"],