There is a heap-based buffer over-read at stb_image_write.h (function: stbi_write_png_to_mem) in libsixel 1.8.2 that will cause a denial of service.
{ "urgency": "not yet assigned" }
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-19759.json"