How severe is CVE-2026-104843?

No CVSS score has been assigned to CVE-2026-104843 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-104843?

CVE-2026-104843 affects the following packages: uv (crates.io), uv (PyPI). Ecosystems affected: crates.io, PyPI.

How do I fix CVE-2026-104843?

Update uv to 0.12.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-104843 is resolved across your whole dependency graph.

How do I detect CVE-2026-104843 in my crates.io, PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uv, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-104843 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-104843 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-104843 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-104843?

CVE-2026-104843 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 36th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-104843?

CVE-2026-104843 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-104843 published, and has it been updated?

CVE-2026-104843 was published on October 2, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀 crates.io🐍 PyPI

Not in CISA KEV

CVE-2026-104843 — uv

Fix: astral-sh/uv@6716964

CVE-2026-104843 is a Path Traversal vulnerability in uv. A fix is available for uv — see the affected versions and patch details below.

uv: Path traversal on Windows through wheel extraction

Also known asGHSA-2cv4-cqwr-gwf7PYSEC-2026-4305

Published

Oct 2, 2026

Updated

Oct 21, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-104843.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs36th percentile — riskier than 36% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

🦀uv🐍uv

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io, PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

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.

Patches

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

Workarounds

There is no workaround other than upgrading to uv 0.12.18.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`uv`	≥ 0.12.7&&< 0.12.18	0.12.18`cargo update -p uv --precise 0.12.18`
🐍PyPI	`uv`	≥ 0.12.7&&< 0.12.18	0.12.18`pip install --upgrade 'uv==0.12.18'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uv, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update uv to 0.12.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-104843 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

Red Hat rates this IMPORTANT vulnerability in uv, a Python package and project manager written in Rust, which is shipped in affected Red Hat offerings across AI and development-tools components. During installation of a Python wheel on Windows, uv could be induced by a maliciously crafted wheel to write files outside…

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. The upstream project reports no workaround other than upgrading; updating to uv 0.12.18 or later, which contains the fix, addresses the issue.

Source: Red Hat security advisory for CVE-2026-104843 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat OpenShift AI 3.4	`rhoai/odh-llm-d-kv-cache-rhel9:1791317861`	RHSA-2026:84734

Frequently Asked Questions

### Impact 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. ### Patches uv 0.12.18 and newer address this vulnerability. Users are encouraged to upgrade to 0.12.18. ### Workarounds There is no workaround other than upgrading to uv 0.12.18.

O3 Security · Impact-Aware SCA

Is CVE-2026-104843 in your dependencies?

Find it across crates.io, PyPI, including transitive dependencies.

Scan my dependencies How O3 SCA works