# MAL-2026-4764: Malicious code in pycalendar-api (PyPI)


- **Type:** Malicious package
- **Package:** `pycalendar-api` (PyPI)
- **Published:** 19 May 2026

## 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.

## Fix prompt for AI coding agents

```text
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)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-4764

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-4764/
Summaries are generated and may contain mistakes; the official description above is the record.