In GraphicsMagick 1.4 snapshot-20171217 Q8, there is a heap-based buffer over-read in ReadMNGImage in coders/png.c, related to accessing one byte before testing whether a limit has been reached.
Severity
CVSS 3.0
8.8 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
1.8% chance of exploitation in the next 30 days; higher than 78% of CVEs (scores of 2026-10-31)