---
id: MAL-2026-18096
title: Malicious code in workalender (PyPI)
summary: Malicious code in workalender (PyPI)
severity: critical
exploited: true
vendor: workalender
product: workalender
ecosystem: pip
affected:
  - workalender
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T14:30:03.703176593Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/MAL-2026-18096'
references:
  - url: 'https://bad-packages.kam193.eu/pypi/package/workalender'
tags:
  - osv
  - pip
  - malware
ingestedAt: '2026-10-21T11:54:42.740Z'
---

## Overview


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

## Source: kam193 (bb4f2824499fd64a22d9dfdb23c454bbb8797422f5281fdd5f454ea64095853a)
Installing the package or importing the module exfiltrates basic information about the host, and the package has no other purpose.


---

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: GENERIC-standard-pypi-install-pentest


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.


 - The package overrides the install command in setup.py to execute malicious code during installation.


## Affected packages

- `workalender`

## Remediation

Refer to the advisory for the patched release.