Juno WordPress Theme Critical RCE Flaw: CVE-2026-62086 Allows Unauth Code Exec in v2.25

The US National Vulnerability Database published details of CVE-2026-62086 on its public registry. This record identifies an unauthenticated PHP object injection flaw within the Juno WordPress theme. The weakness allows attackers to execute arbitrary PHP code on affected servers. The vendor is ThemeREX, a provider of web design templates. The issue impacts installations running version 2.25 or earlier.

Root cause

The underlying problem is mapped to CWE-502, which describes the deserialization of untrusted data. PHP object injection occurs when an application converts a string back into an object without sufficient validation. Attackers craft a malicious string that, when processed, creates objects with harmful properties. This bypasses standard security checks because the application trusts the incoming data structure.

Attack path

An attacker does not need valid user credentials to exploit this vulnerability. They can send a specially crafted request directly to the vulnerable theme files. The server processes this request and deserializes the malicious PHP object. This action leads to remote code execution on the host machine. The attacker gains full control over the compromised web server.

Affected versions

• ThemeREX Juno WordPress theme version 2.25
• All prior versions of the Juno theme
• Any installation running software equal to or older than 2.25

Mitigation

• Verify the installed version of the Juno theme against the affected list
• Monitor server logs for signs of unauthorized PHP object creation
• Implement web application firewalls to block suspicious serialization attempts
• Isolate affected servers from critical network segments if compromise is suspected

Background: National Vulnerability Database

The National Vulnerability Database provides standard identifiers for software flaws. You use these identifiers to automate patching and verify vendor claims. Small teams should cross-reference database entries with their IT asset inventory to prioritise fixes and avoid wasting time on irrelevant alerts.

Read the full guide: National Vulnerability Database: Small Business Action Plan

What to do and how to stay safe: ThemeREX

• Audit all web servers to identify if the Juno WordPress theme is installed
• Check the specific version number to see if it is 2.25 or lower
• Review access logs for unusual POST requests to theme-related endpoints
• Plan to update the theme once the vendor provides a patched version

Step-by-step guide: Security Advisories: 6 Common Misreadings That Leave Systems Exposed

General security guidance from the Vector Bulletin newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

Is this vulnerability critical?

Yes, the US National Vulnerability Database rates CVE-2026-62086 as critical with a score of 9.8.

Which software is affected?

ThemeREX Juno WordPress theme versions up to and including 2.25 are affected.

Do attackers need a password?

No, the vulnerability is unauthenticated, meaning no credentials are required for exploitation.