During garbage collection extra operations were performed on a object that should not be. This could have led to a potentially exploitable crash. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.
bugzilla.mozilla.org/show_bug.cgi?id=1852729
lists.debian.org/debian-lts-announce/2023/10/msg00037.html
lists.debian.org/debian-lts-announce/2023/10/msg00042.html
www.debian.org/security/2023/dsa-5535
www.debian.org/security/2023/dsa-5538
www.mozilla.org/security/advisories/mfsa2023-45/
www.mozilla.org/security/advisories/mfsa2023-46/
www.mozilla.org/security/advisories/mfsa2023-47/