CVE-2026-45753

MEDIUM

Symfony HtmlSanitizer - Cross-Site Scripting via Unsanitized URL Attributes

Title source: manual
STIX 2.1

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.

References (5)

Core 5

Scores

CVSS v3 6.1
EPSS 0.0029
EPSS Percentile 21.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-184 CWE-79
Status published
Products (7)
sensiolabs/symfony 6.1.0 - 6.4.40
symfony/html-sanitizer >= 6.1.0-BETA1, < 6.4.40
symfony/html-sanitizer >= 7.0.0-BETA1, < 7.4.12
symfony/html-sanitizer >= 8.0.0-BETA1, < 8.0.12
symfony/symfony >= 6.1.0-BETA1, < 6.4.40
symfony/symfony >= 7.0.0-BETA1, < 7.4.12
symfony/symfony >= 8.0.0-BETA1, < 8.0.12
Published Jul 14, 2026
Tracked Since Jul 15, 2026