A vulnerability exists in XSLT during number formatting where a negative buffer size may be allocated in some instances, leading to a buffer overflow and crash if it occurs. This vulnerability affects Firefox < 60.
https://www.mozilla.org/security/advisories/mfsa2018-11/
https://usn.ubuntu.com/3645-1/
https://bugzilla.mozilla.org/show_bug.cgi?id=1451908