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Ubuntu 24.04 php-league-commonmark Important XSS Threats USN-8194-1

Several security issues were fixed in league/commonmark.. ========================================================================== Ubuntu Security Notice USN-8194-1 April 21, 2026 php-league-commonmark vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 24.04 LTS - Ubuntu 22.04 LTS - Ubuntu 20.04 LTS Summary: Several security issues were fixed in league/commonmark. Software Description: - php-league-commonmark: Highly-extensible PHP Markdown parser which fully supports the CommonMark and GFM specs Details: It was discovered that league/commonmark did not properly restrict unsafe attributes when the Attributes extension was enabled. An attacker could possibly use this issue to cause cross-site scripting by injecting malicious code into rendered HTML. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2025-46734) It was discovered that league/commonmark did not properly block certain disallowed HTML tags in some cases. An attacker could possibly use this issue to cause cross-site scripting by inserting malicious HTML that bypassed filtering. (CVE-2026-30838) It was discovered that league/commonmark did not properly enforce domain allowlist checks in the Embed extension. An attacker could possibly use this issue to bypass domain restrictions and cause untrusted content to be treated as allowed. This issue only affected Ubuntu 24.04 LTS. (CVE-2026-33347) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 24.04 LTS php-league-commonmark 2.4.2-2ubuntu0.1~esm1 Available with Ubuntu Pro Ubuntu 22.04 LTS php-league-commonmark 1.6.7-1ubuntu0.1~esm1 Available with Ubuntu Pro Ubuntu 20.04 LTS php-league-commonmark 1.3.1-1ubuntu2+esm1 Available with Ubuntu Pro In general,a standard system update will make all the necessary changes. References: https://ubuntu.com/security/notices/USN-8194-1 CVE-2025-46734, CVE-2026-30838, CVE-2026-33347 . Security issues fixed in php-league-commonmark for Ubuntu 20.04 to 24.04. Update recommended for safety.. php league commonmark, Ubuntu security, cross-site scripting, PHP Markdown parser, Ubuntu vulnerabilities. . Severity: Important. LinuxSecurity.com Team

Apr 23, 2026 •Important Ubuntu