CVE-2026-39861

HIGH EPSS 40.1%
Published Apr 21, 20262mo ago · Modified Jun 17, 20261w ago
7.7 CVSS 4.0
High
Find Similar
Published Apr 21, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

Description

Claude Code is an agentic coding tool. Prior to version 2.1.64, Claude Code's sandbox did not prevent sandboxed processes from creating symlinks pointing to locations outside the workspace. When Claude Code subsequently wrote to a path within such a symlink, its unsandboxed process followed the symlink and wrote to the target location outside the workspace without prompting the user for confirmation. This allowed a sandbox escape where neither the sandboxed command nor the unsandboxed app could independently write outside the workspace, but their combination could write to arbitrary locations, potentially leading to code execution outside the sandbox. Reliably exploiting this required the ability to add untrusted content into a Claude Code context window to trigger sandboxed code execution via prompt injection. Users on standard Claude Code auto-update have received this fix automatically. Users performing manual updates are advised to update to version 2.1.64 or later.

CVSS Details

Base Score
7.7
Exploitability
Impact
Vector string
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 P
Scope X

Threat Intelligence

EPSS Exploit Probability
40.1% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 2

CWE-22 Path Traversal Resource Mgmt
CWE-61

Affected Products 1

VendorProductVersionRange
anthropicclaude_code* <2.1.64

References 1

  • github.com https://github.com/anthropics/claude-code/security/advisories/GHSA-vp62-r36r-9xqp
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.