Due to confusion about ValueTags on JavaScript Objects, an object may pass through the type barrier, resulting in memory corruption and a potentially exploitable crash. *Note: this issue only affects Firefox on ARM64 platforms.* This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.