diff --git a/canvas/src/app/orgs/page.tsx b/canvas/src/app/orgs/page.tsx
index 5f1787d6..29a32632 100644
--- a/canvas/src/app/orgs/page.tsx
+++ b/canvas/src/app/orgs/page.tsx
@@ -352,7 +352,8 @@ function CreateOrgForm({ onCreated }: { onCreated: (slug: string) => void }) {
       });
       if (!res.ok) {
         const body = await res.text();
-        throw new Error(`${res.status}: ${body}`);
+        console.error(`[orgs] create ${res.status}: ${body}`);
+        throw new Error(`Failed to create organization (${res.status})`);
       }
       onCreated(slug);
     } catch (e) {
diff --git a/canvas/src/lib/__tests__/billing.test.ts b/canvas/src/lib/__tests__/billing.test.ts
index 9572296c..69c0e1bc 100644
--- a/canvas/src/lib/__tests__/billing.test.ts
+++ b/canvas/src/lib/__tests__/billing.test.ts
@@ -70,7 +70,7 @@ describe("startCheckout", () => {
     expect(body.cancel_url).toContain("checkout=cancel");
   });
 
-  it("throws with the body text on non-2xx so the UI can surface it", async () => {
+  it("throws with status code on non-2xx; body is logged not surfaced", async () => {
     (global.fetch as ReturnType<typeof vi.fn>).mockResolvedValue({
       ok: false,
       status: 402,
@@ -78,8 +78,11 @@ describe("startCheckout", () => {
       json: async () => ({}),
     });
 
+    // Status code must appear so callers know what happened.
     await expect(startCheckout("starter", "acme")).rejects.toThrow(/402/);
-    await expect(startCheckout("starter", "acme")).rejects.toThrow(/payment required/);
+    // Body text must NOT appear — it may contain Stripe API detail.
+    await expect(startCheckout("starter", "acme")).rejects.toThrow(/checkout failed/);
+    await expect(startCheckout("starter", "acme")).rejects.not.toThrow(/payment required/);
   });
 
   it("sends users to /orgs on success, back to current page on cancel", async () => {
diff --git a/canvas/src/lib/billing.ts b/canvas/src/lib/billing.ts
index 35f9833d..c9260e61 100644
--- a/canvas/src/lib/billing.ts
+++ b/canvas/src/lib/billing.ts
@@ -120,8 +120,12 @@ export async function startCheckout(
     }),
   });
   if (!res.ok) {
-    const text = await res.text();
-    throw new Error(`checkout: ${res.status} ${text}`);
+    // Never embed res.text() in the thrown error — the response body
+    // may contain Stripe API error detail (e.g. invalid key, card decline
+    // message, raw Stripe envelope) that should not reach the client.
+    const detail = await res.text();
+    console.error(`[billing] checkout ${res.status}: ${detail}`);
+    throw new Error(`checkout failed (${res.status})`);
   }
   return res.json();
 }
@@ -141,8 +145,12 @@ export async function openBillingPortal(orgSlug: string): Promise<string> {
     body: JSON.stringify({ org_slug: orgSlug, return_url: returnUrl }),
   });
   if (!res.ok) {
-    const text = await res.text();
-    throw new Error(`portal: ${res.status} ${text}`);
+    // Never embed res.text() in the thrown error — the response body
+    // may contain Stripe API error detail (e.g. invalid key, card decline
+    // message, raw Stripe envelope) that should not reach the client.
+    const detail = await res.text();
+    console.error(`[billing] portal ${res.status}: ${detail}`);
+    throw new Error(`portal failed (${res.status})`);
   }
   const data = (await res.json()) as { url: string };
   return data.url;
diff --git a/workspace-server/internal/handlers/admin_test_token.go b/workspace-server/internal/handlers/admin_test_token.go
index 6a2bb9c6..ea005688 100644
--- a/workspace-server/internal/handlers/admin_test_token.go
+++ b/workspace-server/internal/handlers/admin_test_token.go
@@ -18,10 +18,12 @@
 package handlers
 
 import (
+	"crypto/subtle"
 	"database/sql"
 	"log"
 	"net/http"
 	"os"
+	"strings"
 
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/wsauth"
@@ -55,6 +57,20 @@ func (h *AdminTestTokenHandler) GetTestToken(c *gin.Context) {
 		return
 	}
 
+	// IDOR fix (#112, CRITICAL): when ADMIN_TOKEN is set, require it
+	// explicitly. Org-scoped tokens and session cookies must not grant
+	// access — the original gap was that AdminAuth accepted any bearer
+	// that matched a live org token, allowing cross-org token minting.
+	adminSecret := os.Getenv("ADMIN_TOKEN")
+	if adminSecret != "" {
+		tok := c.GetHeader("Authorization")
+		tok = strings.TrimPrefix(tok, "Bearer ")
+		if tok == "" || subtle.ConstantTimeCompare([]byte(tok), []byte(adminSecret)) != 1 {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "admin auth required"})
+			return
+		}
+	}
+
 	workspaceID := c.Param("id")
 	if workspaceID == "" {
 		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
diff --git a/workspace-server/internal/handlers/org_plugin_allowlist.go b/workspace-server/internal/handlers/org_plugin_allowlist.go
index 99672b03..ff58d6ac 100644
--- a/workspace-server/internal/handlers/org_plugin_allowlist.go
+++ b/workspace-server/internal/handlers/org_plugin_allowlist.go
@@ -105,6 +105,61 @@ type putAllowlistRequest struct {
 	EnabledBy string   `json:"enabled_by"` // workspace ID of the admin performing the change
 }
 
+// requireCallerOwnsOrg returns the caller's org workspace ID from the
+// request context, or "" if the caller is not an org-token holder.
+// Used to enforce org isolation on org-scoped routes — the org_token_id
+// is the org-scoped token's ID (not the org workspace ID), so we look
+// it up via the created_by workspace or a direct relationship.
+//
+// Returns ("", nil) when the caller is a session/ADMIN_TOKEN user (they
+// bypass via the session cookie path or ADMIN_TOKEN, not org tokens).
+func requireCallerOwnsOrg(c *gin.Context) (string, error) {
+	tokenID, ok := c.Get("org_token_id")
+	if !ok {
+		return "", nil // not an org-token caller — caller is session/admin
+	}
+	tokID, ok := tokenID.(string)
+	if !ok || tokID == "" {
+		return "", nil
+	}
+	// Look up the org workspace that owns this token.
+	// org_api_tokens has no org_id column, but we can look up the token's
+	// created_by workspace and treat that as the caller's org anchor.
+	var createdBy string
+	err := db.DB.QueryRowContext(c.Request.Context(),
+		`SELECT created_by FROM org_api_tokens WHERE id = $1`, tokID,
+	).Scan(&createdBy)
+	if err != nil || createdBy == "" {
+		// Token has no created_by (CLI bootstrap path) — treat as unowned;
+		// deny by default to prevent cross-org access.
+		return "", fmt.Errorf("token has no org anchor")
+	}
+	return createdBy, nil
+}
+
+// requireOrgOwnership verifies the caller has authority over the target org.
+// Returns 403 and abandons the request if the caller is an org-token holder
+// whose org does not match targetOrgID.
+func requireOrgOwnership(c *gin.Context, targetOrgID string) bool {
+	callerOrg, err := requireCallerOwnsOrg(c)
+	if err != nil {
+		log.Printf("allowlist: requireOrgOwnership: %v", err)
+		c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "org access denied"})
+		return false
+	}
+	// callerOrg "" means session/admin user — they have full access (no
+	// org token → full platform admin via session/ADMIN_TOKEN path).
+	if callerOrg == "" {
+		return true
+	}
+	if callerOrg != targetOrgID {
+		log.Printf("allowlist: org-token org %s tried to access org %s (denied)", callerOrg, targetOrgID)
+		c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "org access denied"})
+		return false
+	}
+	return true
+}
+
 // GetAllowlist handles GET /orgs/:id/plugins/allowlist.
 //
 // Returns the current allowlist for the org workspace identified by :id.
@@ -128,6 +183,13 @@ func (h *OrgPluginAllowlistHandler) GetAllowlist(c *gin.Context) {
 		return
 	}
 
+	// IDOR fix (#112, HIGH): org-token holders must only access their own org.
+	// requireOrgOwnership denies cross-org access (403) while letting session
+	// and ADMIN_TOKEN callers through.
+	if !requireOrgOwnership(c, orgID) {
+		return
+	}
+
 	rows, err := db.DB.QueryContext(ctx, `
 		SELECT plugin_name, enabled_by, enabled_at
 		FROM org_plugin_allowlist
@@ -210,6 +272,11 @@ func (h *OrgPluginAllowlistHandler) PutAllowlist(c *gin.Context) {
 		return
 	}
 
+	// IDOR fix (#112, HIGH): same as GetAllowlist — require org ownership.
+	if !requireOrgOwnership(c, orgID) {
+		return
+	}
+
 	// Replace atomically: delete all current entries, then insert the new set.
 	tx, err := db.DB.BeginTx(ctx, nil)
 	if err != nil {