A high-severity reflected XSS vulnerability (CVE-2026-64638) was identified in the WordPress login interface, affecting all WordPress versions from 4.7 through 7.0.2, with the potential under specific conditions to escalate to PHP code execution. Nexcess proactively notified affected customers and recommended updating to the patched releases (7.0.3, 6.9.6, 6.8.7, or equivalent supported branch versions), with automatic security updates delivering fixes to eligible sites. The incident was resolved on September 2, 2026, with no evidence of widespread exploitation reported throughout the disclosure period.
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The WordPress security vulnerability CVE-2026-64638 has been addressed in the latest WordPress security releases.
Customers are encouraged to keep their WordPress installations updated to the latest available security release within their current supported branch.
We have proactively contacted customers identified as running potentially affected WordPress versions and provided recommendations to update their installations.
At this time, the incident has been resolved, and the related status page notification will be closed.
A high-severity reflected XSS vulnerability, CVE-2026-64638, has been identified in the WordPress login interface. Exploitation requires a victim to visit a specially crafted URL and, under specific conditions, could potentially lead to PHP code execution.
Impacted versions:
WordPress 4.7 – 7.0.2 (every release on every branch)
WordPress 4.6 and earlier — end of life, no patch available
Fixed versions:
WordPress 7.0.3
WordPress 6.9.6
WordPress 6.8.7
Equivalent minor releases on every remaining supported branch back to 4.7
Recommended Action
Customers are strongly encouraged to update WordPress core and ensure automatic security updates are enabled where appropriate. Since exploitation requires user interaction, customers should also remain vigilant against phishing attempts and avoid clicking suspicious or unsolicited links.
Customers with automatic security updates enabled should receive the applicable update automatically; however, we recommend verifying the currently running WordPress version.
There is currently no reported evidence of widespread exploitation in the wild. We will continue to monitor the situation and provide further updates if required.
If you need assistance or have any concerns, please contact our Support team.
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