CVE-2023-45139: Fonttools

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

fontTools is a library for manipulating fonts, written in Python. The subsetting module has a XML External Entity Injection (XXE) vulnerability which allows an attacker to resolve arbitrary entities when a candidate font (OT-SVG fonts), which contains a SVG table, is parsed. This allows attackers to include arbitrary files from the filesystem fontTools is running on or make web requests from the host system. This vulnerability has been patched in version 4.43.0.

Affected products

• Fonttools Fonttools: from 4.28.2, before 4.43.0 (fixed in 4.43.0)

Published 2024-01-10. Last modified 2026-06-17.