updated case to handle binary data

ctx.go

@@ -22,6 +22,7 @@ import (
 	"sync"
 	"text/template"
 	"time"
+	"unicode/utf8"
 
 	"github.com/gofiber/utils/v2"
 	"github.com/valyala/bytebufferpool"
@@ -451,6 +452,11 @@ func (c *DefaultCtx) Cookie(cookie *Cookie) {
 // Make copies or use the Immutable setting to use the value outside the Handler.
 func (c *DefaultCtx) Cookies(key string, defaultValue ...string) string {
 	value := c.app.getString(c.fasthttp.Request.Header.Cookie(key))
+	// If the value looks like binary data, return it as-is
+	if len(value) > 0 && !utf8.ValidString(value) {
+		fmt.Println("Detected non-UTF8 cookie value, returning raw bytes")
+		return value
+	}
 	return defaultString(c.sanitizeCookieValue(value), defaultValue)
 }