Vulnerability · Published Oct 21, 2026 · Assigned by VulnCheck

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

Medium 6.5

In plain English

A medium-severity path traversal in uv from astral-sh. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 72.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Ubuntu:26.10	uv	no fix listed	UBUNTU-CVE-2025-71437

Affected products (as reported)

Vendor	Product	Versions
astral-sh	uv	0 – through 0.8.21

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

References

GitHub Security Advisory (GHSA-7j9j-68r2-f35q) vendor-advisory
VulnCheck Advisory: Astral uv through 0.8.21 Path Traversal via Symlinks in Sdist Tar Extraction third-party-advisory