Critical Zoho Platform Updates December 2025: Security & API Changes You Can't Ignore

Recent Platform Updates

Zoho has rolled out several recent updates that affect how you sync files, respond to support tickets, and integrate with third-party systems. Some are feature enhancements; others are security policy changes that need your attention.

WorkDrive TrueSync: Linux Desktop Support

Zoho WorkDrive desktop app (TrueSync) is now available for Linux as a beta, announced in October 2025, alongside the existing Windows and macOS apps.

What This Means for You

• Supported Distributions: Ubuntu LTS-based distributions (22.04, 24.04 and derivatives) and the latest stable Fedora Workstation
• Developer-Friendly: Development teams using Linux workstations can access WorkDrive files from the desktop without workarounds
• Beta Limitations: Some features are not available yet; for example, the Linux app does not support syncing multiple accounts

Technical Details

The Linux TrueSync client supports:

• Access to WorkDrive files through a virtual drive, without using local storage
• Automatic sync of changes with the WorkDrive web app
• Selective offline access (mark specific files or folders for offline use)
• Sharing files with team members and external collaborators

Zoho Desk: Mass-Reply & AI Enhancements

Zoho Desk updates bring two improvements for support teams: templates and snippets in mass replies, and Zia AI assistance inside tickets.

1. Mass-Reply Templates + Snippets

Agents can now insert email templates and snippets directly from the Mass Reply editor, so they can respond uniformly when handling multiple tickets with similar issues (Professional and Enterprise editions). This is particularly useful for:

• Outage Communications: Send consistent updates to all affected customers
• Product Announcements: Reply to inquiries about new features with standardized responses
• Policy Changes: Ensure all customers receive accurate information
• Seasonal Responses: Holiday hours, shipping updates, or promotional information

2. Zia AI-Powered Assistance

Zia's AI features in Desk offer three key capabilities inside tickets:

• Ticket Summaries: Automatically generate concise summaries of long ticket threads
• Reply Help: Draft replies that combine the ticket conversation with your knowledge base articles
• Insights: Sentiment analysis (positive, neutral or negative) and key-topic tagging

Platform & Automation Essentials

A few core platform behaviors are worth understanding for your integrations and automations:

Bulk Write Async Jobs in CRM

Bulk Write jobs in Zoho CRM are asynchronous: the response isn't available immediately. Here's what you need to know:

• Set a callback URL to be notified when a job completes
• Or check the job status periodically to monitor long-running jobs

Webhook HMAC Signing

Zoho Projects and Zoho Sign can sign webhooks with HMAC-SHA256. Projects sends the signature in the X-ZP-WEBHOOK-SIGNATURE header and Sign in X-ZS-WEBHOOK-SIGNATURE; both are base64-encoded and computed over the raw payload string. Important: always validate these headers in your webhook receivers.

// Example webhook validation (Node.js) - Zoho Projects / Zoho Sign
const crypto = require('crypto');

function validateWebhook(rawBody, signature, secret) {
    // Hash the raw payload string, not re-serialized JSON
    const expected = Buffer.from(crypto
        .createHmac('sha256', secret)
        .update(rawBody)
        .digest('base64'));
    const received = Buffer.from(signature || '');

    return expected.length === received.length &&
        crypto.timingSafeEqual(expected, received);
}

// In your webhook handler
// Projects: x-zp-webhook-signature | Sign: x-zs-webhook-signature
if (!validateWebhook(rawBody, req.headers['x-zp-webhook-signature'], SECRET)) {
    return res.status(401).send('Invalid signature');
}

Records Upsert Semantics

The Records Upsert API checks duplicate-check fields: if a matching record exists, it is updated; otherwise a new record is inserted. Pass duplicate_check_fields to control which fields are checked; if you omit it, system-defined fields are checked first, then user-defined unique fields.

Security-Critical Policy Shifts (Action Required)

This is where you need to pay close attention. Zoho is making two significant security-related changes that will impact how you authenticate API calls and manage OAuth connections.

OAuth Connector Deprecation: January 31, 2026

Revised date: January 31, 2026 (originally December 31, 2025)

Zoho is deprecating the default Zoho OAuth connector in all Zoho services that support Deluge connections, except Zoho Creator. On January 31, 2026, creation of new Zoho OAuth connections will be disabled and the connector will be removed from the default services list. Use service-specific connectors or a custom connector instead.

What's Changing

• Default OAuth Connector Removed: The generic "Zoho OAuth" connector will be removed from the default services list, and new connections can't be created
• Service-Specific Connections: Use the built-in connector for each Zoho service (CRM, Books, Projects, etc.)
• Custom Connectors for Multi-Service Needs: If one connection needs scopes from several Zoho services, create a custom connector
• Existing Connections Keep Working (for Now): Existing Zoho OAuth connections continue to function temporarily; Zoho will deprecate them later, with advance notice to users still relying on them

Why This Matters

The default OAuth connector was convenient, but Zoho cites growing technical complexity and security concerns:

• Broad in scope (one authentication across multiple Zoho services, supporting all of their scopes)
• Service-specific connections follow the principle of least privilege

How to Migrate

1. Audit Your Connections: List all integrations using the default OAuth connector
2. Create Service-Specific Connections: Use each Zoho app's Connections settings (in Zoho CRM: Setup → Developer Hub → Connections)
3. Create Custom Connectors Where Needed: If a connection must span several Zoho services, create a custom connector (you can register your own OAuth client in the Zoho API Console)
4. Update Your Integrations: Replace default OAuth references with new service-specific connections
5. Test Thoroughly: Verify all integrations work with the new connections before January 31, 2026

Deluge invokeURL Security Changes

Status: Already in Effect

Deluge's deprecation of credentials embedded in the invokeURL URL field took effect in September 2025; affected calls now return execution errors. The URL field should contain only the endpoint URL. Use Connections to handle authentication securely.

What Changed

Previously, you could embed a username and password directly in the invokeURL URL field like this:

// NO LONGER SUPPORTED - DO NOT USE
response = invokeurl
[
    url: "https://username:password@api.example.com/endpoint"
    type: GET
];

Use a Connection instead:

// Create a Connection in Zoho first, then reference it
response = invokeurl
[
    url: "https://api.example.com/endpoint"
    type: GET
    connection: "your_connection_name"
];

Why This Change Was Made

• Security: Credentials embedded in URLs can be logged inadvertently in browser histories, proxy servers, or server logs, or exposed through phishing
• Compatibility: Popular browsers and API tools block URLs with embedded credentials
• Rotation: Update credentials in one place (Connection settings) rather than hunting through scripts

How to Update Your Scripts

1. Identify Affected Scripts: Search your Deluge code for invokeURL calls with credentials in the URL (username:password@host)
2. Create Connections: For each external service, create a Connection in Zoho
3. Update invokeURL Calls: Replace embedded credentials with connection references
4. Test Thoroughly: Verify all API calls work with the new Connection-based approach
5. Remove Old Credentials: Delete embedded credentials from your code

Your Action Items Checklist

Here's your prioritized action plan for these December updates:

Need Help with These Updates?

If you're feeling overwhelmed by these security changes or aren't sure where to start, we can help. ZMCOR specializes in Zoho integrations, API development, and platform migrations.

Services We Offer

• OAuth Migration: Audit and migrate from default OAuth to service-specific connections
• Deluge Script Updates: Convert embedded credentials to secure Connections
• Integration Testing: Comprehensive testing to ensure nothing breaks
• Documentation: Document your new connection architecture
• Training: Train your team on new security best practices

Stay Ahead of Zoho Updates

Zoho continues to evolve rapidly, with new features, security improvements, and platform changes announced regularly. December 2025's updates are particularly important because they involve security changes that require action.

The key takeaways:

• WorkDrive TrueSync is now available for Linux (beta) - great for development teams
• Zoho Desk AI features continue to improve support efficiency
• Zoho OAuth connector: new connections can't be created after January 31, 2026 - migrate to service-specific or custom connections
• Credentials embedded in Deluge invokeURL URLs are no longer supported - use Connections

Don't wait until the last minute. Start your migration planning today, test thoroughly, and ensure your integrations continue running smoothly into 2026.