Paper/Archive/CVE-2025-66034

CVE-2025-66034

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

CVSS 9.8 (NVD)9.8 / 10 × 3029.4 Not in CISA KEV+300.0 EPSS percentile 45.8.458 × 209.2 Exploit: SSVC poc+1010.0 SSVC exploitation: poc+100.0

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource

fonttools>= 4.33.0, < 4.60.2–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

GitHub_M (CNA)6.3CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:L

CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: partial

References

exploitgithub.com/fonttools/fonttools/security/advisories/GHSA-768j-98cg-p3fv refgithub.com/fonttools/fonttools/commit/a696d5ba93270d5954f98e7cab5ddca8a02c1e32