Description Contao >=4.0.0 allows backend XSS via HTML attributes to an HTML field. Fixed in 4.4.56, 4.9.18, 4.11.7. Remediation References CVE-2021-35955 Related Vulnerabilities WordPress Plugin Newsletter-Send awesome emails from WordPress Open Redirect (2.6.4.4) Atlassian Jira Exposure of Sensitive Information to an Unauthorized Actor Vulnerability (CVE-2021-39125) Plone CMS Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Vulnerability (CVE-2016-7136) WordPress Plugin Larsens Calender Cross-Site Scripting (1.2) WordPress Plugin Constant Contact for WordPress Unspecified Vulnerability (3.1.6) Severity Medium Classification CVE-2021-35955 CWE-707 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N Tags Missing Update Known Vulnerabilities