CVE-2026-45753

Symfony: HtmlSanitizer UrlAttributeSanitizer Omits action/formaction/poster/cite — javascript: URI Survives Sanitization (XSS)

Published Jul 14, 2026 CVSS 4.0 · 2.1 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, UrlAttributeSanitizer::getSupportedAttributes() omits URL-valued attributes including action, formaction, poster, and cite, so configurations that admit those attributes can leave javascript: URIs unsanitized and enable XSS when the resulting HTML is rendered or a victim submits a form or clicks a button. 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
Github GHSA Github GHSA GHSA-hhg7-c65m-h7ff Symfony's HtmlSanitizer UrlAttributeSanitizer Omits action/formaction/poster/cite — `javascript`: URI Survives Sanitization (XSS)
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, UrlAttributeSanitizer::getSupportedAttributes() omits URL-valued attributes including action, formaction, poster, and cite, so configurations that admit those attributes can leave javascript: URIs unsanitized and enable XSS when the resulting HTML is rendered or a victim submits a form or clicks a button. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.
Title Symfony: HtmlSanitizer UrlAttributeSanitizer Omits action/formaction/poster/cite — javascript: URI Survives Sanitization (XSS)
Weaknesses CWE-184
CWE-79
References
Metrics cvssV4_0

{'score': 2.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 14, 2026, 6:39 PM
Reserved
May 13, 2026, 6:54 AM
Status
Analyzed
Published
Jul 14, 2026, 7:17 PM
Modified
Jul 15, 2026, 1:44 PM