CVE-2026-32104

The updateUserNotifications endpoint accepts a user ID from the request payload and uses it to update that user's notification preferences. It checks that the caller is logged in but never verifies that the caller owns the target account (id !== userData.user.id). Any authenticated visitor can modify notification preferences for any user, including disabling admin notifications to suppress detection of malicious activity.

Details

The vulnerable handler is in packages/studiocms/frontend/pages/studiocms_api/_handlers/dashboard/users.ts:257-311:

.handle(
    'updateUserNotifications',
    Effect.fn(function* ({ payload: { id, notifications } }) {
        // ...demo mode checks...

        const [sdk, userData] = yield* Effect.all([SDKCore, CurrentUser]);

        // Line 274: Only checks login + visitor level, any authenticated user passes
        if (!userData.isLoggedIn || !userData.userPermissionLevel.isVisitor) {
            return yield* new DashboardAPIError({ error: 'Unauthorized' });
        }

        // Line 280: Uses 'id' from payload, NOT userData.user.id
        const existingUser = yield* sdk.GET.users.byId(id);

        // Line 288: Updates target user using attacker-controlled 'id'
        const updatedData = yield* sdk.AUTH.user.update({
            userId: id,       // ← attacker controls this
            userData: {
                id,            // ← attacker controls this
                name: existingUser.name,
                username: existingUser.username,
                updatedAt: new Date().toISOString(),
                emailVerified: existingUser.emailVerified,
                createdAt: undefined,
                notifications,  // ← attacker controls this
            },
        });
    })
)

For comparison, the updateUserProfile handler in dashboard/profile.ts correctly uses userData.user.id instead of a user-supplied ID, preventing IDOR.

PoC

# 1. Log in as a visitor-role user, obtain session cookie

# 2. Disable all notifications for the admin user
curl -X POST 'http://localhost:4321/studiocms_api/dashboard/update-user-notifications' \
  -H 'Cookie: studiocms-session=<visitor-session-token>' \
  -H 'Content-Type: application/json' \
  -d '{
    "id": "<admin-user-id>",
    "notifications": ""
  }'

# Expected: 403 Forbidden
# Actual: 200 {"message":"User notifications updated successfully"}

• Any authenticated visitor can disable notification preferences for admin/owner accounts, suppressing alerts about new user creation, account changes, and user deletions
• Enables attack chaining, suppress admin notifications first, then perform other malicious actions with reduced detection risk
• Can modify any user's notification preferences (enable unwanted notifications or disable critical ones)

CVE-2026-32104 has a CVSS score of 5.4 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.4.3); upgrading removes the vulnerable code path.

Kodem intelligence

Add an ownership check in packages/studiocms/frontend/pages/studiocms_api/_handlers/dashboard/users.ts:

// After the login check at line 274, add:
if (id !== userData.user?.id && !userData.userPermissionLevel.isAdmin) {
    return yield* new DashboardAPIError({
        error: 'Unauthorized: cannot modify another user\'s notification preferences',
    });
}

1. What is CVE-2026-32104? CVE-2026-32104 is a medium-severity security vulnerability in studiocms (npm), affecting versions <= 0.4.2. It is fixed in 0.4.3.
2. How severe is CVE-2026-32104? CVE-2026-32104 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of studiocms are affected by CVE-2026-32104? studiocms (npm) versions <= 0.4.2 is affected.
4. Is there a fix for CVE-2026-32104? Yes. CVE-2026-32104 is fixed in 0.4.3. Upgrade to this version or later.
5. Is CVE-2026-32104 exploitable, and should I be worried? Whether CVE-2026-32104 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-32104 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-32104? Upgrade studiocms to 0.4.3 or later.