On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. This vulnerability affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.
{ "binaries": [ { "binary_version": "1:128.12.0+build1-0ubuntu0.22.04.1", "binary_name": "thunderbird" }, { "binary_version": "1:128.12.0+build1-0ubuntu0.22.04.1", "binary_name": "thunderbird-dev" }, { "binary_version": "1:128.12.0+build1-0ubuntu0.22.04.1", "binary_name": "thunderbird-gnome-support" }, { "binary_version": "1:128.12.0+build1-0ubuntu0.22.04.1", "binary_name": "thunderbird-mozsymbols" }, { "binary_version": "1:128.12.0+build1-0ubuntu0.22.04.1", "binary_name": "xul-ext-calendar-timezones" }, { "binary_version": "1:128.12.0+build1-0ubuntu0.22.04.1", "binary_name": "xul-ext-gdata-provider" }, { "binary_version": "1:128.12.0+build1-0ubuntu0.22.04.1", "binary_name": "xul-ext-lightning" } ] }