# CVE-2025-71437: Astral uv path traversal in sdist tar extraction

Source: https://junglewise.ai/threats/cve-2025-71437-astral-uv-before-0-8-22-contains-a-path-traversal-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2025-71437 · Severity: medium · CVSS 6.5 · Published 2026-10-21

Astral uv is a Python package installer and runner. Versions before 0.8.22 contain a flaw in how they extract source distribution archives, which could allow an attacker to write files outside the intended installation directory when a victim installs a malicious package. While source distributions already execute arbitrary code during installation, this unintended path traversal represents an additional uncontrolled write capability.

Technologies: [Astral Uv](https://junglewise.ai/threats/technologies/astral-uv). Vendors: [Astral](https://junglewise.ai/threats/vendors/astral).

## Quick answers

**Is CVE-2025-71437 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-71437 being exploited in the wild.

**How severe is CVE-2025-71437?** Medium severity, with a CVSS score of 6.5, published 21 October 2026.

**Which products and versions are affected?** Astral Uv before 0.8.22.

**Is there a fix for CVE-2025-71437?** Yes: fixed in 0.8.22 and newer. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-71437 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2025-71437?** Check whether you run Astral Uv at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 0.8.22 and newer

## Technical details

The vulnerability is a path traversal in tar extraction (CWE-22) affecting sdist handling in uv versions ≤0.8.21. An attacker can craft a source distribution with a specially crafted sequence of symlinks that causes the extraction process to write files outside the intended prefix. The attack requires no authentication or user interaction beyond installing a malicious package, but is limited to sdist (source distribution) installs; wheel installations are not affected.

## Affected products

- Astral uv before 0.8.22

## Timeline

- 2025-09-23: disclosed
- 2025-09-23: patched: uv 0.8.22 and newer address the vulnerability

## References

- [https://github.com/astral-sh/uv/security/advisories/GHSA-7j9j-68r2-f35q](https://github.com/astral-sh/uv/security/advisories/GHSA-7j9j-68r2-f35q)
- [https://www.vulncheck.com/advisories/astral-uv-through-0.8.21-path-traversal-via-symlinks-in-sdist-tar-extraction](https://www.vulncheck.com/advisories/astral-uv-through-0.8.21-path-traversal-via-symlinks-in-sdist-tar-extraction)

## Related threats

- [Astral uv arbitrary file deletion through RECORD entries](https://junglewise.ai/threats/duplicate-advisory-uv-vulnerable-to-arbitrary-file-deletion-through-b611c497)
- [Astral uv path traversal via RECORD entries](https://junglewise.ai/threats/cve-2026-114110-astral-uv-before-0-11-6-contains-a-path-traversal-vulnerability)
- [Astral uv path traversal via entry point names](https://junglewise.ai/threats/cve-2026-114109-uv-before-0-11-15-contains-a-path-traversal-vulnerability-that)
- [Astral uv compromised emSign CA root certificate](https://junglewise.ai/threats/pysec-2026-4321-uv-s-bundled-ca-store-trusts-an-emsign-root-whose-aeefabb5)
- [uv bundled CA store trusts compromised emSign root](https://junglewise.ai/threats/uv-s-bundled-ca-store-trusts-an-emsign-root-whose-intermediate-ca-keys-38269068)