Update readme with CVE-2026-65526 fix details

Clarified security enhancement details in the changelog.

Author: kushh23

readme.txt

@@ -280,7 +280,7 @@ Please follow the reporting protocols outlined on our [Security Page](https://th
 
 - Fixed broken candlestick chart
 - Updated dependencies
-- Enhanced security
+- Enhanced security (CVE-2026-65526 fixed)