---
id: "CVE-2026-43637"
page: "https://infrastack.ai/live/CVE-2026-43637"
kind: "vulnerability"
aliases: ["CVE-2026-43637", "GHSA-rrh3-cwwj-g5mg"]
title: "Cornac: Path Traversal via _extract_archive() in download.py"
severity: "critical"
cvss: 9.1
epss: 0.00662
exploited: false
status: "open"
category: "package"
products: [{"name": "cornac", "fixed": ["2.6.0"], "affected": "< 2.6.0", "ecosystem": "pypi"}]
ecosystems: ["pypi"]
tags: ["cornac", "cwe-22", "data-science", "package", "python"]
not_affected_if: ["cornac-2.6.0-or-later", "no-dataset-loaders"]
published_at: "2026-07-15T15:33:06+00:00"
first_seen_at: "2026-11-09T21:50:41+00:00"
updated_at: "2026-11-09T21:51:52+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-rrh3-cwwj-g5mg", "first_seen_at": "2026-11-09T21:50:41+00:00"}]
exploit_sources: [{"type": "epss", "score": 0.00662, "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-43637"}]
---

# Cornac: Path Traversal via _extract_archive() in download.py

Link for people: https://infrastack.ai/live/CVE-2026-43637 (this .md is for agents)

Cornac's dataset downloader extracts TAR archives without checking paths, so a malicious archive can write files anywhere the running process can write. An attacker who controls a downloaded archive can overwrite arbitrary files on the machine running Cornac.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- pypi:cornac affected < 2.6.0 fixed 2.6.0

## How to check

- Run `pip show cornac` and check whether the version is below `2.6.0`.
- Search the project for calls to `_extract_archive` or the built-in dataset loaders, which download and extract archives.

## Fix

- Upgrade `cornac` (PyPI) to `2.6.0`.

## Timeline

- 2026-11-09T21:50:41+00:00 ghsa https://github.com/advisories/GHSA-rrh3-cwwj-g5mg

## Documents

- [fix] Patch: github.com https://github.com/PreferredAI/cornac/pull/709
- [fix] Patch: github.com https://github.com/PreferredAI/cornac/commit/8a50be72c11569b6747c6b96d6e31a0a1962f1a8
- [fix] Release: github.com https://github.com/PreferredAI/cornac/releases/tag/v2.6.0

## From the sources

Cornac before 2.6.0 contains a path traversal (Tar Slip) vulnerability that allows attackers to write arbitrary files outside the intended cache directory by supplying a crafted TAR archive containing ../ sequences, absolute paths, or symlink/hardlink entries to the _extract_archive() function in cornac/utils/download.py. Attackers can trigger this vulnerability through the built-in dataset loaders, which automatically download and extract archives, causing archive.extractall() to write files to arbitrary locations on the filesystem accessible to the running process.

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