CVE-2025-66479: exploitation status and patch state

CVE-2025-66479 · EPSS <1%

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.

Is CVE-2025-66479 exploited?

• Not in the CISA KEV catalog.
• EPSS puts exploitation in the next 30 days at <1%.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2025-66479

• Claude Code Sandbox Bypass Breaks Outbound Trust (2026-05-20)

Primary sources

• NVD record

What this record does not say

• No CVSS score from NVD.
• No affected package data.
• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-08-11.