An exploitable heap out of bounds write vulnerability exists in the Fitz graphical library part of the MuPDF renderer. A specially crafted PDF file can cause a out of bounds write resulting in heap metadata and sensitive process memory corruption leading to potential code execution. Victim needs to open the specially crafted file in a vulnerable reader in order to trigger this vulnerability.
Severity
CVSS 3.1
7.8 high
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
1.7% chance of exploitation in the next 30 days; higher than 77% of CVEs (scores of 2026-10-31)