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.

The remote SUSE Linux SLES15 / openSUSE 15 host has a package installed that is affected by a vulnerability as referenced in the SUSE-SU-2026:0199-1 advisory.

    - CVE-2025-66034: Fixed arbitrary file write vulnerability that could lead to remote code execution     (bsc#1254366).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2025:0963 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2025-66034:
    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.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 42 host has packages installed that are affected by a vulnerability as referenced in the FEDORA-2025-58e2bb0f1e advisory.

    Update to 17.0.0 version (#2412270)     Update fonttools 4.61.0


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.04 / 25.10 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-7917-1 advisory.

    It was discovered that the subsetting module of fontTools was vulnerable to an XML External Entity (XEE)     attack. An unauthenticated remote attacker could possibly use this issue to include arbitrary files from     the file system or make web requests from the host system. This issue only

    affected Ubuntu 22.04 LTS. (CVE-2023-45139)

    It was discovered that fontTools was vulnerable to path traversal attacks. If a user or automated system     were tricked into extracting a specially crafted .designspace file, an attacker could possibly use this     issue to write arbitrary files outside the target directory, resulting in remote code execution. This     issue only affected Ubuntu 24.04 LTS, Ubuntu 25.04 and Ubuntu 25.10. (CVE-2025-66034)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2025-66034)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
294928	SUSE SLES15 / openSUSE 15 Security Update : python-FontTools (SUSE-SU-2026:0199-1)	Nessus	SuSE Local Security Checks	critical
279656	TencentOS Server 4: fonttools (TSSA-2025:0963)	Nessus	Tencent Local Security Checks	critical
279454	Fedora 42 : fonttools / python-unicodedata2 (2025-58e2bb0f1e)	Nessus	Fedora Local Security Checks	critical
278076	Ubuntu 22.04 LTS / 24.04 LTS / 25.04 / 25.10 : fontTools vulnerabilities (USN-7917-1)	Nessus	Ubuntu Local Security Checks	critical
276970	Linux Distros Unpatched Vulnerability : CVE-2025-66034	Nessus	Misc.	critical

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CVE-2025-66034

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