---
id: CVE-2026-48760
aliases:
  - GHSA-v3wm-qf9p-c549
title: >-
  Symfony: HtmlSanitizer URL Parser Deny Gates Underinclusive: Percent-Encoded
  BiDi Marks and Unicode Whitespace Bypass Visual-Spoofing Defense
summary: >-
  Symfony: HtmlSanitizer URL Parser Deny Gates Underinclusive: Percent-Encoded
  BiDi Marks and Unicode Whitespace Bypass Visual-Spoofing Defense
severity: medium
cwe:
  - CWE-451
  - CWE-1007
vendor: symfony
product: symfony/html-sanitizer
ecosystem: composer
affected:
  - 'symfony/html-sanitizer >= 6.1.0, < 6.4.41'
  - 'symfony/html-sanitizer >= 7.0.0, < 7.4.13'
  - 'symfony/html-sanitizer >= 8.0.0, < 8.0.13'
  - 'symfony/symfony >= 6.1.0, < 6.4.41'
  - 'symfony/symfony >= 7.0.0, < 7.4.13'
  - 'symfony/symfony >= 8.0.0, < 8.0.13'
patched:
  - symfony/html-sanitizer 6.4.41
  - symfony/html-sanitizer 7.4.13
  - symfony/html-sanitizer 8.0.13
  - symfony/symfony 6.4.41
  - symfony/symfony 7.4.13
  - symfony/symfony 8.0.13
published: '2026-06-15'
updated: '2026-06-15'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-v3wm-qf9p-c549'
references:
  - url: 'https://github.com/symfony/symfony/security/advisories/GHSA-v3wm-qf9p-c549'
  - url: >-
      https://github.com/symfony/symfony/commit/b21a626fd90f5c12d2db432c629eed3e780ba2f8
  - url: >-
      https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/html-sanitizer/CVE-2026-48760.yaml
  - url: >-
      https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-48760.yaml
  - url: 'https://symfony.com/cve-2026-48760'
  - url: 'https://github.com/advisories/GHSA-v3wm-qf9p-c549'
tags:
  - ghsa
  - composer
ingestedAt: '2026-07-07T15:41:58.730Z'
epss: 0.00338
epssPercentile: 0.27339
---

## Overview

### Description

`Symfony\Component\HtmlSanitizer\TextSanitizer\UrlSanitizer::parse()` rejects URLs containing raw Unicode explicit-direction BiDi formatting characters (U+202A–U+202E, U+2066–U+2069) as a defense against visual-spoofing of the rendered `href`. The check covers only the raw UTF-8 forms of those code points: the percent-encoded forms (`%E2%80%AE` for U+202E, `%E2%81%A6` for U+2066, etc.) are not matched by the deny regex, survive `league/uri`'s parse/build cycle, and are re-emitted unchanged in the sanitized URL. Any downstream consumer that decodes the link before display — phishing-detection filters that compare `urldecode($href)` against a domain allow-list, audit-log dashboards that show a decoded form for readability, hover-tooltip previews, federated/syndicated content where the decoder lives on the consuming side — restores the BiDi character and the visual spoof that the original defense was filed to prevent.

The same `UrlSanitizer::parse()` carries an ASCII-only `/\s/` whitespace check (no `/u` modifier) intended as a backstop against malformed URLs. Without the `/u` modifier, PCRE's `\s` matches only ASCII whitespace, so Unicode whitespace characters — NBSP (U+00A0), the zero-width no-break space / BOM (U+FEFF), line/paragraph separators (U+2028, U+2029), ogham space (U+1680), the U+2000–U+200A en/em quad family, narrow / medium / ideographic spaces (U+202F, U+205F, U+3000) and NEL (U+0085) — pass through unchanged in both raw and percent-encoded forms. In hostname positions they enable lookalike spoofs (`example<NBSP>.com`); in path/query/fragment they enable allow-list drift when a downstream consumer strips whitespace before comparison.

### Resolution

`UrlSanitizer::parse()` now denies BiDi formatting marks together with Unicode whitespace and the zero-width no-break space, in both the raw input and the percent-decoded form of each parsed URL component (`user`, `pass`, `host`, `path`, `query`, `fragment`). ASCII space remains tolerated in path/query/fragment via the existing percent-encoding step.

The patches for this issue are available [here](https://github.com/symfony/symfony/commit/b21a626fd90f5c12d2db432c629eed3e780ba2f8) for branch 6.4 (and forward-ported to 7.4, 8.0 and 8.1).

### Credits

Symfony would like to thank Scott Arciszewski (Trail of Bits) for reporting the issue and Nicolas Grekas for providing the fix.

## Affected packages

- `symfony/html-sanitizer >= 6.1.0, < 6.4.41`
- `symfony/html-sanitizer >= 7.0.0, < 7.4.13`
- `symfony/html-sanitizer >= 8.0.0, < 8.0.13`
- `symfony/symfony >= 6.1.0, < 6.4.41`
- `symfony/symfony >= 7.0.0, < 7.4.13`
- `symfony/symfony >= 8.0.0, < 8.0.13`

## Remediation

Upgrade to a patched release:

- `symfony/html-sanitizer 6.4.41`
- `symfony/html-sanitizer 7.4.13`
- `symfony/html-sanitizer 8.0.13`
- `symfony/symfony 6.4.41`
- `symfony/symfony 7.4.13`
- `symfony/symfony 8.0.13`