PoC Index

CVE-2025-66034

CRITICAL 9.8EPSS 0.5%

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 vulnerability affects the main() code path of fontTools.varLib, used by the fonttools varLib CLI and any code that invokes fontTools.varLib.main(). This issue has been patched in version 4.60.2.

CVSS v3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v3.1
6.3 MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:L
CVSS v3.1
6.3 MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:L
EPSS
0.55% chance of exploitation in the next 30 days, 44th percentile
Published
2025-11-29
Updated
2025-12-01

Proof-of-concept exploits (7)

References

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