CVE-2026-104843 astral-sh CVE debrief

Who should care

Windows hosts using uv within the affected version range should assess exposure and upgrade to version 0.12.18 or later. Users of affected versions should verify the integrity of installed packages and monitor for suspicious activity. Security teams should review compensating controls for exposed systems while remediation is scheduled and verified.

Why it matters

This path traversal vulnerability in uv on Windows hosts requires immediate attention from users of affected versions. Upgrading to version 0.12.18 or later is crucial to prevent potential exploitation.

• Potential placement of executables on the user's PATH
• Possible execution of malicious code outside intended environment
• Need for verification of installed package integrity
• Priority for upgrading to uv version 0.12.18 or later

Technical summary

The vulnerability allows a malicious wheel to place an executable outside the intended environment on Windows hosts using uv versions 0.12.7 to 0.12.18. This is addressed in uv version 0.12.18 and later. The vulnerability can be exploited during wheel installation, and users of affected versions should assess their exposure and upgrade to version 0.12.18 or later to mitigate this vulnerability. The vulnerability requires immediate attention from users of affected versions, and upgrading to version 0.12.18 or later is crucial to prevent potential exploitation.

Defensive priority

Upgrade to uv 0.12.18 or later to mitigate this vulnerability. Assess exposure for Windows hosts using uv within the affected version range.

Recommended defensive actions

• Upgrade to uv version 0.12.18 or later
• Assess exposure for Windows hosts using uv within the affected version range
• Verify the integrity of installed packages and monitor for suspicious activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is confirmed in uv versions 0.12.7 to 0.12.18 on Windows. Official sources indicate that upgrading to version 0.12.18 addresses this issue. The vulnerability allows a malicious wheel to place an executable outside the intended environment, potentially on the user's PATH. This issue requires immediate attention from users of affected versions.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.