Description
fontTools is a library for manipulating fonts, written in Python. The subsetting module has a XML External Entity Injection (XXE) vulnerability which allows an attacker to resolve arbitrary entities when a candidate font (OT-SVG fonts), which contains a SVG table, is parsed. This allows attackers to include arbitrary files from the filesystem fontTools is running on or make web requests from the host system. This vulnerability has been patched in version 4.43.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| fonttools | fonttools | >= 4.28.2, < 4.43.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | fonttools | 4.46.0-1 | — |
| Debian 13 | fonttools | 4.46.0-1 | — |
| Debian 12 | fonttools | 4.38.0-1+deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 25.10 | fonttools | 4.55.3-2ubuntu0.25.10.1 | USN-7917-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | fonttools | 4.46.0-1ubuntu0.1~esm1 | USN-7917-1 |
| Ubuntu Pro 22.04 LTS | fonttools | 4.29.1-2ubuntu0.1~esm1 | USN-7917-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-FontTools | 4.62.1-1.3 | openSUSE-SU-2026:11991-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | fonttools | >= 4.28.2, < 4.43.0 | 4.43.0 | GHSA-6673-4983-2vx5 |
Advisories 3
- openSUSE-SU-2026:11991-1 python313-FontTools-4.62.1-1.3 on GA media SUSE / openSUSE Security Updates · Oct 5, 2026
- USN-7917-1 fonttools vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- WID-SEC-2024-3377 Dell PowerProtect Data Domain: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 12, 2025
References
- https://github.com/fonttools/fonttools/security/advisories/GHSA-6673-4983-2vx5
- https://github.com/fonttools/fonttools/commit/9f61271dc1ca82ed91f529b130fe5dc5c9bf1f4c
- https://github.com/fonttools/fonttools/releases/tag/4.43.0
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VY63B4SGY4QOQGUXMECRGD6K3YT3GJ75/
- http://www.openwall.com/lists/oss-security/2024/03/09/1
- http://www.openwall.com/lists/oss-security/2024/03/08/2