# Bug Report: Infinite Recursion in Pods Alternative Cache

[oxfordmetadata]

Bug Report: Infinite Recursion in Pods Alternative Cache

Plugin Information

• Plugin: Pods Alternative Cache
• Version: 2.2.1
• WordPress Version: 6.x
• PHP Version: 8.x

Summary

The Pods Alternative Cache plugin causes a fatal PHP stack overflow error due to infinite recursion when current_user_can() is called during cache purge operations.

Steps to Reproduce

1. Have Pods Alternative Cache plugin active
2. Have a caching plugin installed (e.g., WP Rocket, SG Optimizer)
3. Trigger a cache purge from the admin dashboard
4. Visit: /wp-admin/admin-post.php?action=purge_cache&type=all

Expected Behavior

Cache should be purged without errors.

Actual Behavior

PHP Fatal Error with stack overflow:

PHP Fatal error: Uncaught Error: Maximum call stack size of 8339456 bytes
(zend.max_allowed_stack_size - zend.reserved_stack_size) reached. Infinite recursion?

in /public_html/wp-includes/plugin.php:173

Stack trace:
#0 wp-includes/plugin.php(173): apply_filters()
#1 wp-includes/capabilities.php(879): map_meta_cap()
#2 wp-includes/class-wp-user.php(790): WP_User->has_cap()
#3 wp-includes/capabilities.php(1021): user_can()
#4 wp-includes/capabilities.php(914): current_user_can()
#5 wp-content/plugins/pods-alternative-cache/classes/Pods/Alternative/Cache.php(116): current_user_can()

Root Cause Analysis

The plugin hooks into a capability-related filter (likely user_has_cap or map_meta_cap) and calls current_user_can() inside that hook. This creates an infinite recursion loop:

current_user_can()
  → map_meta_cap()
    → apply_filters()
      → Pods\Alternative\Cache hook (line 116)
        → current_user_can()  ← RECURSION STARTS HERE
          → map_meta_cap()
            → apply_filters()
              → Pods\Alternative\Cache hook
                → current_user_can()
                  → ... (continues until stack overflow)

Suggested Fix

Add a static recursion guard in the affected method in Cache.php:

// In classes/Pods/Alternative/Cache.php

private static $is_checking_capability = false;

public function your_capability_filter_method($allcaps, $caps, $args, $user) {
    // Prevent infinite recursion
    if (self::$is_checking_capability) {
        return $allcaps;
    }

    self::$is_checking_capability = true;

    try {
        // Your existing logic that calls current_user_can()
        if (current_user_can('some_capability')) {
            // ...
        }
    } finally {
        self::$is_checking_capability = false;
    }

    return $allcaps;
}

Environment Details

• Server: Cloudways (nginx + PHP-FPM)
• Object Cache: Redis (Object Cache Pro)
• Caching Plugin: WP Rocket / SG Optimizer

Workaround

Currently deactivating the plugin to prevent the error:

wp plugin deactivate pods-alternative-cache

Additional Notes

• The error only occurs during specific admin operations that trigger capability checks
• The recursion happens at Cache.php line 116
• This appears to be a logic error where current_user_can() should not be called inside a capability filter, or needs recursion protection

Contact

Feel free to reach out if you need additional debugging information or access to error logs.

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Reported: 2025-12-16