Cross-site scripting (XSS) vulnerability in the Attributes extension of the league/commonmark library (versions 1.5.0 through 2.6.x) allows remote attackers to insert malicious JavaScript calls into HTML.
Several polynomial time complexity issues in league/commonmark may lead to unbounded resource exhaustion and subsequent denial of service. Malicious users could trigger that inefficient code with carefully crafted Markdown inputs that are specifically designed to ensure the worst-case performance is reached. Sending multiple such requests in parallel could tie up all available CPU resources and/or PHP-FPM processes, leading to denial of service for legitimate users.
Cross-site scripting (XSS) vulnerability in the PHP League CommonMark library allows remote attackers to insert unsafe links into HTML by using double-encoded HTML entities that are not properly escaped during rendering, a different vulnerability than CVE-2018-20583.
Cross-site scripting (XSS) vulnerability in the PHP League CommonMark library allows remote attackers to insert unsafe URLs into HTML (even if allow_unsafe_links is false) via a newline character (e.g., writing javascript as javascri%0apt).