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 Blog2Social:Social Media Auto Post & Scheduler Unspecified Vulnerability (5.1.2) Apache Tomcat Exposure of Sensitive Information to an Unauthorized Actor Vulnerability (CVE-2007-3382) Liferay DXP CVE-2022-42126 Vulnerability (CVE-2022-42126) MySQL CVE-2018-2586 Vulnerability (CVE-2018-2586) OpenSSL Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability (CVE-2006-3738) 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 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N Tags Missing Update Known Vulnerabilities