How to fix CVE-2025-65099?

Within 30 days: Identify all affected systems running a project via yarn plugins and apply vendor patches as part of regular patch cycle. Validate that input sanitization is in place for all user-controlled parameters.

Is Claude Code affected by CVE-2025-65099?

Organizations using a project via yarn plugins face notable risk from CVE-2025-65099, a code injection vulnerability rated CVSS 7.7. Successful exploitation could allow attackers to execute arbitrary code or commands on affected systems, potentially leading to full system compromise.

CVE-2025-65099

HIGH

2025-11-19 [email protected]

7.7

CVSS 4.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Scope

Lifecycle Timeline

Patch Released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 28, 2026 - 19:23 vuln.today

CVE Published

Nov 19, 2025 - 18:15 nvd

HIGH 7.7

Description

Claude Code is an agentic coding tool. Prior to version 1.0.39, when running on a machine with Yarn 3.0 or above, Claude Code could have been tricked to execute code contained in a project via yarn plugins before the user accepted the startup trust dialog. Exploiting this would have required a user to start Claude Code in an untrusted directory and to be using Yarn 3.0 or above. This issue has been patched in version 1.0.39.

Analysis

Claude Code is an agentic coding tool. Rated high severity (CVSS 7.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical Context

This vulnerability is classified as Code Injection (CWE-94), which allows attackers to inject and execute arbitrary code within the application. Claude Code is an agentic coding tool. Prior to version 1.0.39, when running on a machine with Yarn 3.0 or above, Claude Code could have been tricked to execute code contained in a project via yarn plugins before the user accepted the startup trust dialog. Exploiting this would have required a user to start Claude Code in an untrusted directory and to be using Yarn 3.0 or above. This issue has been patched in version 1.0.39. Affected products include: Anthropic Claude Code. Version information: version 1.0.39.

Affected Products

Anthropic Claude Code.

Remediation

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Never evaluate user-controlled input as code. Use sandboxing, disable dangerous functions, apply strict input validation.

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +0.2

CVSS: +38

POC: 0

CVE-2025-65099 vulnerability details – vuln.today

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CVE-2025-65099

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CVE-2025-65099

CVSS Vector

Lifecycle Timeline

Tags

Description

Analysis

Technical Context

Affected Products

Remediation

Priority Score

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External POC / Exploit Code