I was also able to fix this issue by upgrading libnss3: Package: firefox (amd64) Version: 48.0-2
$ sudo apt install libnss3=2:3.26-1 Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: libnss3-1d The following packages will be upgraded: libnss3 1 upgraded, 0 newly installed, 1 to remove and 1 not upgraded. Need to get 1,158 kB of archives. After this operation, 46.1 kB disk space will be freed. Do you want to continue? [Y/n] Get:1 http://ftp.us.debian.org/debian unstable/main amd64 libnss3 amd64 2:3.26-1 [1,158 kB] Fetched 1,158 kB in 0s (2,444 kB/s) Retrieving bug reports... Done Parsing Found/Fixed information... Done Reading changelogs... Done (Reading database ... 292437 files and directories currently installed.) Removing libnss3-1d:amd64 (2:3.25-1) ... (Reading database ... 292430 files and directories currently installed.) Preparing to unpack .../libnss3_2%3a3.26-1_amd64.deb ... Unpacking libnss3:amd64 (2:3.26-1) over (2:3.25-1) ... Setting up libnss3:amd64 (2:3.26-1) ... Processing triggers for libc-bin (2.23-5) ...