MAL-2026-4764 Malicious code in pycalendar-api (PyPI)
Malicious package
Published
MAL-2026-4764 is a malicious package: pycalendar-api (PyPI). Every version was published to cause harm.
Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.
Reference: https://insights.sbomify.com/MAL-2026-4764/ (Markdown: https://insights.sbomify.com/MAL-2026-4764/index.md)
- Package
- pycalendar-api
- Registry
- PyPI
What is MAL-2026-4764?
MAL-2026-4764 is a malicious package in pycalendar-api, published on 19 May 2026.
Official description
pyproject.toml line 8 declares
httpxyz as a runtime dependency (dependencies = ['httpxyz',...]), and pycalendar_api/utils/http_client.py imports httpxyz and exercises an API surface (httpxyz.Client, httpxyz.AsyncClient, httpxyz.Timeout, httpxyz.HTTPTransport, httpxyz.AsyncHTTPTransport, event_hooks) that is byte-identical to the well-known httpx HTTP client. httpxyz is not a recognized mainstream PyPI package; the name is a clear typosquat of httpx, and the README links to a non-canonical https://httpxyz.org. Any pip install pycalendar-api will resolve and install whatever package owns the name httpxyz on PyPI onto the installer's machine — a silent transitive that the installer never asked for and that mimics a legitimate library. This is the namespace-abuse / dependency-confusion shape: the lure package uses a typosquat name as a hard dependency to drag attacker-controlled (or attacker-claimable) code into every installer's environment, while presenting a legitimate-looking API.What should I do about MAL-2026-4764?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.