Async JS and CSS Security & Risk Analysis

wordpress.org/plugins/async-js-and-css

Converts render-blocking CSS and JS files into NON-render-blocking, improving performance of web page.

800 active installs v1.7.13 PHP + WP 2.6+ Updated Nov 28, 2017
asyncasynchronousheadjsjavascriptjs
85
A · Safe
CVEs total0
Unpatched0
Last CVENever
Safety Verdict

Is Async JS and CSS Safe to Use in 2026?

Generally Safe

Score 85/100

Async JS and CSS has no known CVEs and is actively maintained. It's a solid choice for most WordPress installations.

No known CVEs Updated 8yr ago
Risk Assessment

The "async-js-and-css" plugin v1.7.13 presents a mixed security posture. On the positive side, the plugin demonstrates excellent practices by avoiding dangerous functions and exclusively using prepared statements for its SQL queries, indicating a strong defense against common injection attacks. Furthermore, the absence of recorded vulnerabilities in its history suggests a generally well-maintained codebase. The plugin also has no identified CVEs, which is a significant strength.

However, there are notable areas of concern stemming from the static analysis. The most significant risk lies in the complete lack of output escaping for all 13 identified output points. This represents a substantial vulnerability to Cross-Site Scripting (XSS) attacks, as user-supplied or indirectly controlled data could be rendered directly in the browser without sanitization. Additionally, the absence of nonce and capability checks on any entry points, while the attack surface is currently reported as zero, means that if any new entry points are introduced or existing ones are repurposed without proper authentication and authorization, these vulnerabilities could be easily exploited. The single file operation also warrants scrutiny to ensure it's handled securely.

Key Concerns

  • Output escaping is completely missing
  • No nonce checks on entry points
  • No capability checks on entry points
  • File operation without specified checks
Vulnerabilities
None known

Async JS and CSS Security Vulnerabilities

No known vulnerabilities — this is a good sign.
Code Analysis
Analyzed Mar 16, 2026

Async JS and CSS Code Analysis

Dangerous Functions
0
Raw SQL Queries
0
0 prepared
Unescaped Output
13
0 escaped
Nonce Checks
0
Capability Checks
0
File Operations
1
External Requests
0
Bundled Libraries
0

Output Escaping

0% escaped13 total outputs
Attack Surface

Async JS and CSS Attack Surface

Entry Points0
Unprotected0
WordPress Hooks 13
actionplugins_loadedasyncJSandCSS.php:14
actioninitasyncJSandCSS.php:50
actionwp_print_stylesasyncJSandCSS.php:61
actionwp_footerasyncJSandCSS.php:62
actionwp_headasyncJSandCSS.php:67
actionwp_footerasyncJSandCSS.php:68
actionwp_print_scriptsasyncJSandCSS.php:73
actionwp_headasyncJSandCSS.php:76
actionwp_headasyncJSandCSS.php:77
actionwp_footerasyncJSandCSS.php:82
actionwp_footerasyncJSandCSS.php:83
actionadmin_menusettings_page.php:3
actionadmin_initsettings_page.php:106
Maintenance & Trust

Async JS and CSS Maintenance & Trust

Maintenance Signals

WordPress version tested3.7.41
Last updatedNov 28, 2017
PHP min version
Downloads114K

Community Trust

Rating84/100
Number of ratings51
Active installs800
Developer Profile

Async JS and CSS Developer Profile

dmikam

2 plugins · 830 total installs

84
trust score
Avg Security Score
85/100
Avg Patch Time
30 days
View full developer profile
Detection Fingerprints

How We Detect Async JS and CSS

Patterns used to identify this plugin on WordPress sites during automated security audits and web crawling.

Asset Fingerprints

Asset Paths
/wp-content/plugins/async-js-and-css/asyncJSandCSS.php/wp-content/plugins/async-js-and-css/settings_page.php/wp-content/plugins/async-js-and-css/functions.php
Script Paths
/wp-content/plugins/async-js-and-css/asyncJSandCSS.php
Version Parameters
async-js-and-css/style.css?ver=async-js-and-css/script.js?ver=

HTML / DOM Fingerprints

HTML Comments
<!--script-->
JS Globals
asyncScriptsasyncFunctionsloadedScriptsscriptsToLoadexecOnReady
FAQ

Frequently Asked Questions about Async JS and CSS