{"cve":"CVE-2025-66034","nvd":{"published":"2025-11-29T01:16:02.967","modified":"2026-10-18T18:10:00.100","status":"Analyzed","description":"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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-91"],"references":["https://github.com/fonttools/fonttools/commit/a696d5ba93270d5954f98e7cab5ddca8a02c1e32","https://github.com/fonttools/fonttools/security/advisories/GHSA-768j-98cg-p3fv","https://github.com/fonttools/fonttools/security/advisories/GHSA-768j-98cg-p3fv"],"products":["fonttools:fonttools"],"source":"nvd","synced_at":"2026-10-19T22:16:02.354564667+00:00"},"epss":{"cve":"CVE-2025-66034","score":0.00547,"percentile":0.45591,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-768j-98cg-p3fv","url":"https://osv.dev/vulnerability/GHSA-768j-98cg-p3fv","summary":"fontTools is Vulnerable to Arbitrary File Write and XML injection in fontTools.varLib","modified":"2026-09-10T03:50:31.754255627Z","packages":[{"ecosystem":"PyPI","name":"fonttools","purl":"pkg:pypi/fonttools","ranges":[">=4.33.0 <4.60.2"],"fixed":["4.60.2"]}]},{"id":"PYSEC-2026-1389","url":"https://osv.dev/vulnerability/PYSEC-2026-1389","summary":"fontTools is Vulnerable to Arbitrary File Write and XML injection in fontTools.varLib","modified":"2026-07-07T17:47:21.823307009Z","packages":[{"ecosystem":"PyPI","name":"fonttools","purl":"pkg:pypi/fonttools","ranges":[">=4.33.0 <4.60.2"],"fixed":["4.60.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}