The .sethalftone5 function in psi/zht2.c in Ghostscript before 9.21 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted Postscript document that calls .sethalftone5 with an empty operand stack.
Severity
CVSS 3.0
7.8 high
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
3.2% chance of exploitation in the next 30 days; higher than 88% of CVEs (scores of 2026-10-31)