1.8
LOW CVSS 4.0
CVE-2025-66479
Anthropic Sandbox Runtime Incorrectly Implemented Network Sandboxing
Description

Anthropic Sandbox Runtime is a lightweight sandboxing tool for enforcing filesystem and network restrictions on arbitrary processes at the OS level, without requiring a container. Prior to 0.0.16, due to a bug in sandboxing logic, sandbox-runtime did not properly enforce a network sandbox if the sandbox policy did not configure any allowed domains. This could allow sandboxed code to make network requests outside of the sandbox. A patch for this was released in v0.0.16.

INFO

Published Date :

Dec. 4, 2025, 9:16 p.m.

Last Modified :

April 15, 2026, 12:35 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2025-66479 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 LOW [email protected]
Solution
Update Anthropic Sandbox Runtime to version 0.0.16 or later to fix network restriction enforcement.
  • Update Anthropic Sandbox Runtime to 0.0.16.
  • Verify sandbox network policies are correctly configured.
  • Apply patches to address sandbox logic bugs.
Public PoC/Exploit Available at Github

CVE-2025-66479 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-66479.

URL Resource
https://github.com/anthropic-experimental/sandbox-runtime/commit/bea2930cc1db9c73a1b15acf6dc19c5261aec1f3
https://github.com/anthropic-experimental/sandbox-runtime/security/advisories/GHSA-9gqj-5w7c-vx47
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-66479 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-66479 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Secure on-device agent for Comet browser — MCP server with OS-level sandboxing (bubblewrap/sandbox-exec), filesystem tools, and allow listed terminal execution. Claude Code-style isolation for agentic file editing and command running.

TypeScript HTML Shell JavaScript

Updated: 1 month, 1 week ago
0 stars 0 fork 0 watcher
Born at : April 12, 2026, 2:18 p.m. This repo has been linked 1 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-66479 vulnerability anywhere in the article.

  • CybersecurityNews
Claude Code’s Network Sandbox Vulnerability Exposes User Credentials and Source Code

Anthropic’s Claude Code AI coding assistant harbored a critical network sandbox bypass for over five months, allowing attackers to exfiltrate credentials, source code, and environment variables from d ... Read more

Published Date: May 21, 2026 (7 hours, 43 minutes ago)

The following table lists the changes that have been made to the CVE-2025-66479 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Dec. 04, 2025

    Action Type Old Value New Value
    Added Description Anthropic Sandbox Runtime is a lightweight sandboxing tool for enforcing filesystem and network restrictions on arbitrary processes at the OS level, without requiring a container. Prior to 0.0.16, due to a bug in sandboxing logic, sandbox-runtime did not properly enforce a network sandbox if the sandbox policy did not configure any allowed domains. This could allow sandboxed code to make network requests outside of the sandbox. A patch for this was released in v0.0.16.
    Added CVSS V4.0 AV:L/AC:L/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/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
    Added CWE CWE-693
    Added Reference https://github.com/anthropic-experimental/sandbox-runtime/commit/bea2930cc1db9c73a1b15acf6dc19c5261aec1f3
    Added Reference https://github.com/anthropic-experimental/sandbox-runtime/security/advisories/GHSA-9gqj-5w7c-vx47
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.