fontus

GHSA-g5mh-f2v3-6p25

Malicious code in fontus (PyPI)

Details

**Severity:** Critical

**Affected versions:** `= 0.0.1`

## Source: kam193 (2a8fcff0fd4d827c6f174318ee41ea82eb2667c6d65349a01ca2215aa2f4dd5e)
The package most likely performs fingerprinting by exfiltrating basic information and available fonts, with no other functionality.


---

Category: PROBABLY_PENTEST - Packages looking like typical pentest packages, but also anything that looks like testing, exploring pre-prepared kits, research & co, with clearly low-harm possibilities.


Campaign: 2026-10-fontus


Reasons (based on the campaign):


 - The package contains code to exfiltrate basic data from the system, like IP or username. It has a limited risk.

---

Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/18bac9af384479dd8c9d2977916dad65e852f834/osv/malicious/pypi/fontus/MAL-2026-18271.json))

**References:**
- https://bad-packages.kam193.eu/pypi/package/fontus
- https://github.com/ossf/malicious-packages/blob/18bac9af384479dd8c9d2977916dad65e852f834/osv/malicious/pypi/fontus/MAL-2026-18271.json
- https://github.com/advisories/GHSA-g5mh-f2v3-6p25

Compromised versions (1)

= 0.0.1

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.