The Odd Bug Where Jetpack Protect Interfered With XML-RPC and Broke Remote Publishing — How I Diagnosed and Solved It

Recently, while working on a client’s WordPress site, I encountered a frustrating and puzzling issue: XML-RPC-based remote publishing suddenly stopped working. This functionality is crucial for users who manage content from external apps or automate posts via services such as IFTTT or Zapier. After hours of research, testing, and reverse engineering, I pinned the culprit down to a surprising source — Jetpack Protect. Below, I’ll walk you through how I discovered the problem, the process I followed to fix it, and what you can learn to avoid similar issues in your WordPress setup.

TL;DR

Remote publishing using XML-RPC in WordPress was inexplicably broken. After tracing the issue through logs and experimenting with plugin deactivation, I found that Jetpack Protect was silently blocking XML-RPC requests. Disabling the specific component resolved the issue. If remote publishing features stop working, scrutinize your security plugins — especially Jetpack’s Protect module.

The Symptoms: When Remote Publishing Quietly Fails

It started with a client reporting that their automated content processes were no longer pushing updates to their WordPress site. This involved publishing articles via external tools relying on the XML-RPC interface — a long-standing API for WordPress that allows remote interactions such as posting, editing or managing comments.

Here’s what they noticed:

• Articles scheduled via Zapier would fail silently.
• Mobile apps using WordPress’s Remote Publishing feature couldn’t connect.
• No recent changes had been made on the hosting server or to WordPress core.

At first glance, everything appeared intact. I tested the xmlrpc.php endpoint manually and got a valid 200 response. No fatal errors. However, connections from remote clients would get rejected or time out — inconsistent behavior that made debugging more difficult.

Digging Further: Ruling Out the Usual Suspects

I began by checking the most common potential causes:

1. Hosting Restrictions: Some shared hosts disable XML-RPC or block certain types of traffic. That wasn’t the case here — the site was on a bespoke VPS with full access to logs and services.
2. Firewall Configurations: I examined the server firewall and endpoint rules—everything checked out. No requests were being filtered at the network layer.
3. XML-RPC File Accessibility: I loaded the xmlrpc.php endpoint directly and received a plain-text message: “XML-RPC server accepts POST requests only.” This is expected and confirmed the file wasn’t physically missing.

At this stage, I was confident the problem wasn’t infrastructural — it had to be within WordPress or one of its plugins.

Clue in the Logs: An Unexpected Block Behavior

Checking the Apache error logs yielded nothing. But the access logs showed connections to /xmlrpc.php followed by an immediate disconnect or a 403 Forbidden status. Strange — I tried disabling a few plugins manually to see whether anything changed.

The breakthrough came after I disabled Jetpack entirely and XML-RPC requests began working again. That gave me the direction I needed. Step-by-step, I reactivated Jetpack and disabled components one by one from the settings.

That’s when I found it: the Jetpack Protect module was silently intercepting and denying remote XML-RPC calls.

Why Jetpack Protect Was to Blame

Jetpack Protect is designed to safeguard your WordPress site from malicious threats such as brute-force attacks and malware injections. However, in its effort to fortify critical entry points, it also monitors interactions with xmlrpc.php — one of the older and more vulnerable gateways in WordPress.

That alone isn’t shocking. What confused me was how quietly it operated:

• No admin alerts or dashboard notifications were thrown.
• Nothing appeared in Jetpack logs within wp-admin.
• The block didn’t resemble normal rate-limiting; it was a permanent hard stop.

The logic was likely built to block any behavior that “resembles” bot activity — a poor match for automated publishing tools that use API keys or app credentials.

The Solution: Disabling or Reconfiguring Jetpack Protect

Depending on your needs, there are two ways to correct this without compromising overall security:

1. Disable Jetpack Protect:

   This is the bluntest, simplest fix and is often adequate if you’re running other security layers such as Cloudflare, WAF, or a server-based firewall. You can do this from the Jetpack dashboard:

   • Go to Jetpack › Settings › Security.
   • Toggle off Protect.
2. Whitelist XML-RPC traffic:

   Dig into Jetpack’s filter hook documentation and manually whitelist specific IPs or services you trust. This requires adding snippets like:

   
   function custom_jetpack_protect_whitelist($whitelist) {
     $whitelist[] = 'ipadress.of.trusted.service';
     return $whitelist;
   }
   add_filter('jetpack_protect_whitelist_ip', 'custom_jetpack_protect_whitelist');
   

   While more complicated, it’s a more targeted approach that keeps Protect in place for common attacks while maintaining app connectivity.

The Importance of XML-RPC Today

There’s been a push over recent years to recommend disabling xmlrpc.php entirely due to its long history of being exploited. However, that’s not always practical:

• Mobile applications still rely on it for publishing and comment moderation.
• External tools like Zapier, IFTTT, and custom integrations use it routinely.
• Some older APIs or publishing platforms haven’t updated to REST API yet.

Until the REST API reaches full parity and industry-wide adoption, XML-RPC remains a necessary piece — especially for users automating workflows or managing multiple sites remotely.

Lessons Learned and Final Thoughts

The odd part of this entire issue wasn’t technical—it’s that a plugin designed to help quietly caused a major service failure, and in doing so, obfuscated the very thing it was interfering with. This reinforces a few key best practices:

• Test critical features after installing or updating security plugins. Even passive filters can disrupt workflows.
• Log everything when debugging. Server access logs often contain better clues than plugin messages.
• Prefer modular plugins with granular control. Jetpack tries to do a lot, and sometimes that breadth comes at the cost of clarity.

For developers and site administrators, awareness is 90% of the game. Knowing that Jetpack Protect might silently block XML-RPC calls gives you a clear avenue to start from when troubleshooting publishing disruptions in the future.

Conclusion

Diagnosing the XML-RPC issue caused by Jetpack Protect was a textbook example of digging deeper than surface-level diagnostics. If you rely on remote publishing tools or support clients who do, this is your notice: Jetpack Protect may be a hidden barrier you didn’t know was there. Catch it before it interrupts your workflow.