CVE-2026-45753
Published:July 14, 2026
Updated:July 21, 2026
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.
Affected Packages
symfony/symfony (PHP):
Affected version(s) >=v8.0.0 <v8.0.12Fix Suggestion:
Update to version v8.0.12symfony/html-sanitizer (PHP):
Affected version(s) >=v7.0.0 <v7.4.12Fix Suggestion:
Update to version v7.4.12symfony/html-sanitizer (PHP):
Affected version(s) >=v8.0.0 <v8.0.12Fix Suggestion:
Update to version v8.0.12symfony/html-sanitizer (PHP):
Affected version(s) >=v6.1.0 <v6.4.40Fix Suggestion:
Update to version v6.4.40symfony/symfony (PHP):
Affected version(s) >=v7.0.0 <v7.4.12Fix Suggestion:
Update to version v7.4.12symfony/symfony (PHP):
Affected version(s) >=v6.1.0 <v6.4.40Fix Suggestion:
Update to version v6.4.40Related Resources (10)
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Contact UsCVSS v4
Base Score:
2.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
ACTIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
Exploit Maturity
UNREPORTED
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.30