Firefox and Thunderbird are vulnerable to a use-after-free vulnerability. The vulnerability is due to incorrect reference counting, where assigning an AlignedBuffer to itself can lead to an incorrect reference count and subsequent use-after-free.
bugzilla.mozilla.org/show_bug.cgi?id=1883158
lists.debian.org/debian-lts-announce/2024/04/msg00012.html
lists.debian.org/debian-lts-announce/2024/04/msg00013.html
security-tracker.debian.org/tracker/CVE-2024-3861
www.mozilla.org/security/advisories/mfsa2024-18/
www.mozilla.org/security/advisories/mfsa2024-19/
www.mozilla.org/security/advisories/mfsa2024-20/