CVE-2020-26956

En algunos casos, al eliminar unos elementos HTML durante el saneamiento mantendría los actuales manejadores de eventos SVG y, por lo tanto, conllevaría a un ataque de tipo XSS. Esta vulnerabilidad afecta a Firefox versiones anteriores a 83, Firefox ESR versiones anteriores a 78.5, y Thunderbird versiones anteriores a 78.5

USN-4637-1 fixed vulnerabilities in Firefox. This update provides the corresponding updates for Ubuntu 16.04 LTS. Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information across origins, bypass security restrictions, conduct phishing attacks, conduct cross-site scripting attacks, bypass Content Security Policy restrictions, conduct DNS rebinding attacks, or execute arbitrary code. Various other issues were also addressed.