CVE-2026-104843

uv: Path traversal on Windows through wheel extraction

Workarounds

There is no workaround other than upgrading to uv 0.12.18.

In versions of uv from 0.12.7 to 0.12.18 on Windows, uv could be induced into writing a file outside of the installation prefix during wheel installation.

A malicious wheel could use this to place an executable outside of the intended environment, including in a directory already present on the user's PATH.

This vulnerability only affects Windows hosts; no other platforms are affected.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

Kodem intelligence

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uv 0.12.18 and newer address this vulnerability. Users are encouraged to upgrade to 0.12.18.

1. What is CVE-2026-104843? CVE-2026-104843 is a medium-severity path traversal vulnerability in uv (pip), affecting versions >= 0.12.7, < 0.12.18. It is fixed in 0.12.18. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. Which versions of uv are affected by CVE-2026-104843? uv (pip) versions >= 0.12.7, < 0.12.18 is affected.
3. Is there a fix for CVE-2026-104843? Yes. CVE-2026-104843 is fixed in 0.12.18. Upgrade to this version or later.
4. Is CVE-2026-104843 exploitable, and should I be worried? Whether CVE-2026-104843 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2026-104843 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2026-104843?
   • Upgrade uv to 0.12.18 or later
   • Upgrade uv to 0.12.18 or later

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