CVE-2025-71437: Astral uv through 0.8.21 Path Traversal via Symlinks in Sdist Tar Extraction

Q: Who is exposed to this issue?

Users of Astral uv versions before 0.8.22 are exposed when they install a malicious source distribution (sdist). Exploitation requires the victim to install the attacker-published package.

Q: What access does an attacker need?

The attacker does not need prior privileges on the victim system, but must be able to cause the victim to install a specially crafted sdist. The victim must perform the installation, so user interaction is required.

Q: What is the impact of a successful exploit?

A crafted sequence of symlinks in the sdist tar archive can redirect extraction writes outside the intended installation prefix. This can allow arbitrary file writes to filesystem locations accessible to the installation process.

Q: Which versions should be remediated?

Upgrade Astral uv to version 0.8.22 or later. Versions through 0.8.21 are affected.

Published Oct 21, 2026

Updated

Astral uv before 0.8.22 contains a path traversal vulnerability in source distribution (sdist) tar extraction that allows a specially crafted sequence of symlinks to redirect file writes outside the intended extraction prefix. Attackers can publish a malicious sdist that, when installed by a victim, writes arbitrary files to filesystem locations outside the installation prefix.

Affected Software

1 affected component

pypi/uv<0.8.22

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Astral uv to a version that resolves this vulnerability.
Fixed in 0.8.22

Event History

Oct 21, 2026

CVE Published

via MITRE·12:36 AM

Data Sourced

via MITRE·12:36 AM

DescriptionSeverityWeakness

Frequently Asked Questions

Who is exposed to this issue?

Users of Astral uv versions before 0.8.22 are exposed when they install a malicious source distribution (sdist). Exploitation requires the victim to install the attacker-published package.

What access does an attacker need?

The attacker does not need prior privileges on the victim system, but must be able to cause the victim to install a specially crafted sdist. The victim must perform the installation, so user interaction is required.

What is the impact of a successful exploit?

A crafted sequence of symlinks in the sdist tar archive can redirect extraction writes outside the intended installation prefix. This can allow arbitrary file writes to filesystem locations accessible to the installation process.

Which versions should be remediated?

Upgrade Astral uv to version 0.8.22 or later. Versions through 0.8.21 are affected.

CVE-2025-71437: Astral uv through 0.8.21 Path Traversal via Symlinks in Sdist Tar Extraction

Affected Software

Remediation

Event History

Frequently Asked Questions

Who is exposed to this issue?

What access does an attacker need?

What is the impact of a successful exploit?

Which versions should be remediated?

Company

Resources

Contact

Frequently Asked Questions

Who is exposed to this issue?

What access does an attacker need?

What is the impact of a successful exploit?

Which versions should be remediated?