Logo
-

Byte Open Security

(ByteOS Network)

Log In

Sign Up

ByteOS

Security
Vulnerability Details
Registries
Custom Views
Weaknesses
Attack Patterns
Filters & Tools
NVD Vulnerability Details :
CVE-2025-66034
Analyzed
More InfoOfficial Page
Source-security-advisories@github.com
View Known Exploited Vulnerability (KEV) details
Published At-29 Nov, 2025 | 01:16
Updated At-03 Dec, 2025 | 21:50

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.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary3.16.3MEDIUM
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:L
Primary3.19.8CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Type: Secondary
Version: 3.1
Base score: 6.3
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:L
Type: Primary
Version: 3.1
Base score: 9.8
Base severity: CRITICAL
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CPE Matches
fonttools
fonttools
>>fonttools>>Versions from 4.33.0(inclusive) to 4.60.2(exclusive)
cpe:2.3:a:fonttools:fonttools:*:*:*:*:*:python:*:*
Weaknesses
CWE IDTypeSource
CWE-91Secondarysecurity-advisories@github.com
CWE ID: CWE-91
Type: Secondary
Source: security-advisories@github.com
Evaluator Description
Evaluator Impact

Evaluator Solution

Vendor Statements
References
HyperlinkSourceResource
https://github.com/fonttools/fonttools/commit/a696d5ba93270d5954f98e7cab5ddca8a02c1e32security-advisories@github.com
Patch
https://github.com/fonttools/fonttools/security/advisories/GHSA-768j-98cg-p3fvsecurity-advisories@github.com
Exploit
Vendor Advisory
https://github.com/fonttools/fonttools/security/advisories/GHSA-768j-98cg-p3fv134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit
Vendor Advisory
Hyperlink: https://github.com/fonttools/fonttools/commit/a696d5ba93270d5954f98e7cab5ddca8a02c1e32
Source: security-advisories@github.com
Resource:
Patch
Hyperlink: https://github.com/fonttools/fonttools/security/advisories/GHSA-768j-98cg-p3fv
Source: security-advisories@github.com
Resource:
Exploit
Vendor Advisory
Hyperlink: https://github.com/fonttools/fonttools/security/advisories/GHSA-768j-98cg-p3fv
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Resource:
Exploit
Vendor Advisory
Change History
0Changes found
Details not found