POC-CVE-2025-66034

fontvarlib.py — CVE-2025-66034 fontTools varLib — Arbitrary File Write + XML Injection → Remote Code Execution Table of Contents Overview Vulnerability Details Attack Chain Requirements Installation Configuration Usage How It Works Vulnerable Code Pre-Exploitation Checklist Tested On Disclaimer...

varlib-cve-2025-66034

fontTools varLib CVE-2025-66034 Exploit This repo doesn't introduce a new vulnerability. This is a Proof-of-concept exploit for CVE-2025-66034 affecting the fontTools varLib variable font generation pipeline. The vulnerability allows attackers to control the output filename inside a crafted...

CVE-2025-66034

CVE-2025-66034 — fontTools varLib Arbitrary File Write → RCE PoC exploit for an Arbitrary File Write + XML Injection vulnerability infontTools.varLib Tested on HackTheBox — VarIaType Vulnerability fontTools.varLib processes .designspace XML files to build variable fonts. Two weaknesses combine to...

CVE-2025-66034

CVE-2025-66034 — fontTools varLib Arbitrary File Write Vulnerability fontTools is a Python library for manipulating font files. Its varLib module processes .designspace files — an XML format that describes how multiple font masters should be interpolated to produce a variable font. Two weaknesses...

PYSEC-2026-1389 fontTools is Vulnerable to Arbitrary File Write and XML injection in fontTools.varLib

Summary The fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The vulnerability affects the main code path of fontTools.varLib, used by the fonttools varLib CLI and...

fontTools is Vulnerable to Arbitrary File Write and XML injection in fontTools.varLib

SummaryThe fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The vulnerability affects the main code path of fontTools.varLib, used by the fonttools varLib CLI and a...

Exploit for XML Injection (aka Blind XPath Injection) in Fonttools

CVE-2025-66034 — fontTools varLib Arbitrary File Write → RCE...

Exploit for XML Injection (aka Blind XPath Injection) in Fonttools

fontvarlib.py — CVE-2025-66034 fontTools varLib — Arbi...

Arbitrary File Write

fontTools is vulnerable to an arbitrary file write. The vulnerability is due to improper handling of malicious .designspace files in the fontTools.varLib module, which allows an attacker to achieve remote code execution by writing arbitrary files when processed...

CVE-2025-66034

This vulnerability in fontTools varLib allows a crafted .designspace file to trigger arbitrary file writes and XML-based content injection during variable-font generation. Because filenames are not sanitized, an attacker can use path traversal to overwrite files anywhere on the filesystem, and...

SUSE CVE-2025-66034

fontTools is a library for manipulating fonts, written in Python. In versions from 4.33.0 to before 4.60.2, the fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The...

GHSA-768J-98CG-P3FV fontTools is Vulnerable to Arbitrary File Write and XML injection in fontTools.varLib

Summary The fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The vulnerability affects the main code path of fontTools.varLib, used by the fonttools varLib CLI and...

fontTools is Vulnerable to Arbitrary File Write and XML injection in fontTools.varLib

Summary The fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The vulnerability affects the main code path of fontTools.varLib, used by the fonttools varLib CLI and...

DEBIAN-CVE-2025-66034

fontTools is a library for manipulating fonts, written in Python. In versions from 4.33.0 to before 4.60.2, the fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The...

CVE-2025-66034

fontTools is a library for manipulating fonts, written in Python. In versions from 4.33.0 to before 4.60.2, the fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The...

UBUNTU-CVE-2025-66034

fontTools is a library for manipulating fonts, written in Python. In versions from 4.33.0 to before 4.60.2, the fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The...

CVE-2025-66034

fontTools is a library for manipulating fonts, written in Python. In versions from 4.33.0 to before 4.60.2, the fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The...

CVE-2025-66034 fontTools is Vulnerable to Arbitrary File Write and XML injection in fontTools.varLib

fontTools is a library for manipulating fonts, written in Python. In versions from 4.33.0 to before 4.60.2, the fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The...

CVE-2025-66034 fontTools is Vulnerable to Arbitrary File Write and XML injection in fontTools.varLib

fontTools is a library for manipulating fonts, written in Python. In versions from 4.33.0 to before 4.60.2, the fonttools varLib or python3 -m fontTools.varLib script has an arbitrary file write vulnerability that leads to remote code execution when a malicious .designspace file is processed. The...

CVE-2025-66034

CVE-2025-66034 affects fontTools, a Python font manipulation library. Affected: fontTools.varLib main() path when processing malicious .designspace files; arbitrary file write can lead to remote code execution. Impact: high (per CVSS 3.1, base 9.8) when exploited via the varLib CLI or code invoki...