CVE-2026-45066

Symfony: HtmlSanitizer allowLinkHosts() / allowMediaHosts() Bypass via URL-Parser Differentials and <area> Misclassification

Published Jul 14, 2026 CVSS 4.0 · 2.3 Low EPSS < 1% KEV · Not listed
Description
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowlist URLs through allowLinkHosts() or allowMediaHosts() because UrlSanitizer::parse() follows RFC 3986 while browsers follow WHATWG URL parsing, and because <area href> is checked against the media policy rather than the link policy. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6312-1 symfony security update
Github GHSA Github GHSA GHSA-qc95-4862-92fh Symfony has an HtmlSanitizer allowLinkHosts() / allowMediaHosts() Bypass via URL-Parser Differentials and <area> Misclassification
History
Type Values Removed Values Added
First Time appeared Symfony
Symfony html-sanitizer
Symfony symfony
Vendors & Products Symfony
Symfony html-sanitizer
Symfony symfony
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowlist URLs through allowLinkHosts() or allowMediaHosts() because UrlSanitizer::parse() follows RFC 3986 while browsers follow WHATWG URL parsing, and because <area href> is checked against the media policy rather than the link policy. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.
Title Symfony: HtmlSanitizer allowLinkHosts() / allowMediaHosts() Bypass via URL-Parser Differentials and <area> Misclassification
Weaknesses CWE-184
CWE-436
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 16, 2026, 2:29 PM
Reserved
May 8, 2026, 6:45 PM
Status
Analyzed
Published
Jul 14, 2026, 6:17 PM
Modified
Jul 16, 2026, 3:16 PM