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CVE-2025-66479VulnerabilityPublished

CVE-2025-66479: anthropic-experimental sandbox-runtime · Protection Mechanism Failure

Affects anthropic-experimental sandbox-runtimeSource CVE Database V5

0

Not known to be exploited · CVSS 1.8 Low : upgrade to 0.0.16 when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score
1.8Low
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 0.0.16
CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 4 Dec 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Upgrade anthropic-experimental/sandbox-runtime to 0.0.16.

Affected software

ProductAffectedFixed in
GitHubanthropic-experimental/sandbox-runtimepkg:github/anthropic-experimental/sandbox-runtimeOther threatsAffected
  • <0.0.16
Fixed in
  • 0.0.16

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Upgrade anthropic-experimental sandbox-runtime to version 0.0.16 or later immediately to apply the official patch that fixes the network sandbox enforcement bug. 2. Review and audit sandbox policies to ensure that network restrictions are explicitly and correctly configured, avoiding empty allowed domain lists that could trigger the vulnerability. 3. Implement strict access controls to limit who can deploy or modify sandbox policies and who can run sandboxed processes with high privileges. 4. Monitor network traffic originating from sandboxed processes for any anomalous or unauthorized connections, using network intrusion detection systems tailored to sandbox environments. 5. Employ defense-in-depth by combining sandboxing with other security controls such as endpoint detection and response (EDR) tools and application whitelisting. 6. Conduct regular security assessments and penetration tests focusing on sandbox configurations and enforcement mechanisms. 7. Educate developers and system administrators about the importance of correct sandbox policy configuration and the risks of misconfiguration.

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.

References

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