WordPress Release: 4.5.27

TL;DR

WordPress 4.5.27 Security Release

This maintenance release focuses on security improvements for WordPress 4.5. It includes several important security fixes that address output escaping vulnerabilities and improves the security of bookmark queries. Additionally, the release updates GitHub Actions workflows to enhance the development infrastructure, particularly around Slack notifications.

Highlight of the Release

• Security fixes for output escaping in the_meta() function
• Improved validation for bookmark query limits
• Enhanced error message escaping in plugins
• Updated GitHub Actions workflows for better development infrastructure

Migration Guide

No migration steps are required for this security update. Site administrators should update to WordPress 4.5.27 as soon as possible to ensure their sites are protected against the security vulnerabilities addressed in this release.

Upgrade Recommendations

It is strongly recommended that all WordPress sites running version 4.5.x update to version 4.5.27 immediately. This security release addresses multiple vulnerabilities that could be exploited if left unpatched.

While WordPress 4.5 is no longer officially supported with regular updates, this security release has been provided as a courtesy to sites that have not yet upgraded to more recent WordPress versions. However, site administrators should plan to upgrade to a current, fully-supported WordPress version as soon as possible.

Bug Fixes

Security-Related Bug Fixes

• Posts/Post Types: Fixed output escaping within the the_meta() function to prevent potential XSS vulnerabilities.
• General: Added validation to ensure bookmark query limits are numeric, preventing potential SQL injection.
• Plugins: Improved escaping of output in error messages to prevent potential XSS vulnerabilities.

New Features

No significant new features were added in this maintenance release. WordPress 4.5.27 focuses primarily on security fixes and infrastructure improvements for the development workflow.

Security Updates

This release addresses several security vulnerabilities:

• Output Escaping in Post Meta: Fixed improper output escaping in the the_meta() function that could potentially allow XSS attacks when displaying post meta data.
• Bookmark Query Validation: Added proper validation to ensure bookmark query limits are numeric, preventing potential SQL injection attacks.
• Plugin Error Messages: Enhanced escaping of output in plugin error messages to prevent potential XSS vulnerabilities.

These security fixes help protect WordPress sites from potential cross-site scripting (XSS) and SQL injection attacks.

Performance Improvements

No specific performance improvements were included in this release. The changes focus on security fixes and development workflow enhancements rather than performance optimizations.

Impact Summary

WordPress 4.5.27 is a security-focused maintenance release that addresses several important vulnerabilities. By fixing output escaping issues in post meta display, ensuring bookmark query limits are properly validated, and enhancing error message escaping in plugins, this release helps protect WordPress sites from potential XSS and SQL injection attacks.

While this release doesn't introduce new features or performance improvements, it demonstrates WordPress's commitment to providing security updates even for older branches that are technically out of the regular support cycle. The infrastructure improvements to GitHub Actions workflows, particularly around Slack notifications, benefit the WordPress development community by streamlining the development process.

Site administrators should prioritize this update to maintain the security of their WordPress installations, while also planning for an eventual upgrade to a fully-supported WordPress version.