Description Cross-site Scripting (XSS) vulnerability in MyBB before 1.8.26 via Nested Auto URL when parsing messages. Remediation References CVE-2021-27889 Related Vulnerabilities Atlassian Jira Authorization Bypass Through User-Controlled Key Vulnerability (CVE-2021-41307) WordPress Plugin iubenda-All-in-one Compliance for GDPR/CCPA Cookie Consent + more Privilege Escalation (3.3.2) Python Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability (CVE-2016-0718) WordPress Plugin Contact Form by Supsystic Cross-Site Scripting (1.7.19) silverstripeCMS Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') Vulnerability (CVE-2019-5715) Severity Medium Classification CVE-2021-27889 CWE-707 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Tags Missing Update Known Vulnerabilities