---
id: 5047
title: "Bypassing character blocklists with unicode overflows"
source_domain: portswigger.net
source_url: "https://portswigger.net/research/bypassing-character-blocklists-with-unicode-overflows"
published_at: "2025-01-29 08:10"
tags: ["burp-suite", "web-security", "unicode", "filter-bypass", "character-encoding", "truncation"]
phying_url: "https://phying.com/item/5047"
lang: en
---

# Bypassing character blocklists with unicode overflows

## Summary

Unicode codepoint truncation turns overflow values into blocked ASCII characters — 0x4e41 % 256 yields 'A' — bypassing character blocklists; the trick now ships in ActiveScan++ and Hackvertor.

## Intelligence Metadata

- **Sources:** portswigger.net
- **Published:** 2025-01-29 08:10
- **Original:** https://portswigger.net/research/bypassing-character-blocklists-with-unicode-overflows
- **Phying News:** https://phying.com/item/5047