A double-free bug in the read_gif function in gifread.c in gifsicle 1.90 allows a remote attacker to cause a denial-of-service attack or unspecified other impact via a maliciously crafted file, because last_name is mishandled, a different vulnerability than CVE-2017-1000421.
https://github.com/kohler/gifsicle/issues/117
https://github.com/kohler/gifsicle/commit/118a46090c50829dc543179019e6140e1235f909