---
id: "MAL-2026-15863"
kind: "package"
aliases: ["MAL-2026-15863"]
title: "Malicious code in uvhttp-custom (PyPI)"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "uvhttp-custom", "fixed": [], "affected": "= 1.7.9; = 1.8.1; = 1.9.9", "ecosystem": "pypi"}]
ecosystems: ["pypi"]
tags: ["malicious", "package"]
not_affected_if: []
published_at: "2026-09-03T16:52:46+00:00"
first_seen_at: "2026-10-26T20:51:56+00:00"
updated_at: "2026-10-26T21:12:36+00:00"
sources: [{"source": "osv-malicious", "url": "https://osv.dev/vulnerability/MAL-2026-15863", "first_seen_at": "2026-10-26T20:51:56+00:00"}]
---

# Malicious code in uvhttp-custom (PyPI)

## Affected

- pypi:uvhttp-custom affected = 1.7.9; = 1.8.1; = 1.9.9 fixed ?

## Timeline

- 2026-10-26T20:51:56+00:00 osv-malicious https://osv.dev/vulnerability/MAL-2026-15863

## From the sources

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

## Source: amazon-inspector (bf8bf69e0edd8a79c920c35d2c49e722b38d801c07401dfb673bdb1beb6ea3fc)
setup.py contains an obfuscated payload of the form `(lambda __: exec(__import__('base64').b64decode('...').decode()))(None)` alongside an otherwise-benign setuptools import. The decoded payload writes a bundled script.ps1 to disk and invokes `powershell -ExecutionPolicy Bypass -File script.ps1`. The PowerShell script uses System.Net.WebClient.DownloadFile to fetch a Windows executable from cdn.discordapp.com/attachments/1532996358427115552/1539384056284717066/enlisted_launcher_1.0.3.190-movn8hpfe.exe into %TEMP%\file.exe and launches it via Start-Process with -WindowStyle Hidden. No hash or signature verification is performed. The payload also invokes `os.system("calc")`. Running `pip install uvhttp-custom` on Windows therefore causes the installer's machine to download and silently execute an opaque, unsigned binary from an anonymous Discord CDN URL.

## Source: kam193 (9d56fe693f2b6e693e195640269a9ad95c8ab5eb94c897bbc711e897177c4cc6)
During installation, obfuscated code downloads and executes an executable. It appears to be a game launcher.


---

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.


Campaign: 2026-09-uvhttp-custom


Reasons (based on the campaign):


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


 - Downloads and executes a remote executable.


 - obfuscation

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