Memory safety bugs present in Firefox 114, Firefox ESR 102.12, and Thunderbird 102.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 115, Firefox ESR < 102.13, and Thunderbird < 102.13.
https://www.mozilla.org/security/advisories/mfsa2023-24/
https://www.mozilla.org/security/advisories/mfsa2023-23/
https://www.mozilla.org/security/advisories/mfsa2023-22/
https://www.debian.org/security/2023/dsa-5451
https://www.debian.org/security/2023/dsa-5450
https://lists.debian.org/debian-lts-announce/2023/07/msg00015.html
https://lists.debian.org/debian-lts-announce/2023/07/msg00006.html
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1832306%2C1834862%2C1835886%2C1836550%2C1837450