Module load requests that failed were not being checked as to whether or not they were cancelled causing a use-after-free in <code>ScriptLoadContext</code>. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.
https://www.mozilla.org/security/advisories/mfsa2023-07/
https://www.mozilla.org/security/advisories/mfsa2023-06/