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CVE-2026-45753

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

Published: Jul 14, 2026Updated: Jul 15, 2026 Sources: CVE List NVDCWE-79
6.1MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 78.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:CC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-79CWE-184

Affected Products

symfony
oss-projectaka symfony framework, twig (related)
symfonyLibrary
OSS Libraries / web-framework
html-sanitizerLibrary
OSS Libraries / web-framework
sensiolabs
oss-project
symfonyLibraryLibrary
OSS Libraries / generic-library

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Execution
Initial Access
View detailed technique mapping

References

https://github.com/symfony/symfony/commit/487728e7e180a674a6d4c01bd0cb56161cc441b7
github.com
https://github.com/symfony/symfony/releases/tag/v6.4.40
github.com
https://github.com/symfony/symfony/releases/tag/v7.4.12
github.com
and 2 more references View all →

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