Mozilla Firefox could allow a remote attacker to obtain sensitive information, caused by an out-of-bounds read when drawing text characters onto a Canvas. By persuading a victim to visit a specially-crafted Web site, a remote attacker could exploit this vulnerability to obtain sensitive information. This bug only affects Firefox on Windows. Other operating systems are unaffected.
Mozilla Firefox 88.0.0
Upgrade to the latest version of Mozilla Firefox (89.0.1) from https://www.mozilla.org/en-US/security/advisories/mfsa2021-27/