---
id: MAL-2026-18271
title: Malicious code in fontus (PyPI)
summary: Malicious code in fontus (PyPI)
severity: critical
exploited: true
vendor: fontus
product: fontus
ecosystem: pip
affected:
  - fontus
published: '2026-10-25'
updated: '2026-10-29'
sourceUpdated: '2026-10-29T14:45:09.337393094Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/MAL-2026-18271'
references:
  - url: 'https://bad-packages.kam193.eu/pypi/package/fontus'
  - url: 'https://pypi.org/project/fontus/0.0.2/'
  - url: 'https://pypi.org/project/fontus/0.0.1/'
  - url: 'https://pypi.org/project/fontus/0.0.3/'
tags:
  - osv
  - pip
  - malware
ingestedAt: '2026-10-26T12:01:30.293Z'
---

## Overview


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_-= Per source details. Do not edit below this line.=-_

## Source: amazon-inspector (bb5b8b4484126f787f9917d91b6815927146a308f64bfb852c57f5d60bf4bfbb)
Analysis of fontus 0.0.3 on PyPI did not identify any code paths that exfiltrate installer data, execute attacker-controlled payloads at install or import time, relay caller-supplied data to third-party destinations, distribute live credentials, or establish persistence. No install-time network fetches, no lifecycle shell execution, no reads of credential paths (~/.aws, ~/.ssh, ~/.npmrc, browser profiles), and no obfuscated or dynamic-exec patterns were observed.

## 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.


## Affected packages

- `fontus`

## Remediation

Refer to the advisory for the patched release.