The ReadWPGImage function in coders/wpg.c in GraphicsMagick 1.3.26 does not properly validate colormapped images, which allows remote attackers to cause a denial of service (ImportIndexQuantumType invalid write and application crash) or possibly have unspecified other impact via a malformed WPG image.
http://hg.code.sf.net/p/graphicsmagick/code/rev/e8086faa52d0
https://lists.debian.org/debian-lts-announce/2018/08/msg00002.html
Source: MITRE
Published: 2017-11-05
Updated: 2018-10-18
Type: CWE-476
Base Score: 6.8
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 8.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 2.8
Severity: HIGH