URL Redirection to Untrusted Site ('Open Redirect')
Requests initiated through reader mode did not properly omit cookies with a SameSite attribute. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
CWE-601 - Open Redirect
An open redirect attack employs a URL parameter, HTML refresh tags, or a DOM based location change to exploit the trust of a vulnerable domain to direct the users to a malicious website. The attack could lead to higher severity vulnerabilities such as unauthorized access control, account takeover, XSS, and more.