CVE-2025-66032Network attack vector

Arbitrary code execution via shell parser bypass

Published Dec 3, 2025 · Updated Dec 3, 2025

Command injection in Anthropic Claude Code before 1.0.93 allows remote attackers to execute arbitrary code through crafted context content. Its read-only command validator misparses shell commands that use $IFS or short CLI flags, allowing disallowed command syntax to pass validation. Exploitation requires untrusted content to enter the context window; successful commands run with the privileges available to the Claude Code process.

CVSS severity8.7
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Anthropic Claude Code before 1.0.93 allows remote attackers to execute arbitrary code through crafted context content. Its read-only command validator misparses shell commands that use $IFS or short CLI flags, allowing disallowed command syntax to pass validation. Exploitation requires untrusted content to enter the context window; successful commands run with the privileges available to the Claude Code process.

The record

CVE
CVE-2025-66032
Published
Dec 3, 2025
Updated
Dec 3, 2025
Vendor
Anthropic
Product
Claude Code
Classifications
CWE-77, CWE-20, T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 3, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.0.93

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Anthropic · Claude Codeversion=< 1.0.93

Published CVSS scores

8.7Anthropic GitHub Security AdvisoryCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
CWE-20Improper Input Validation
T1059.004Command and Scripting Interpreter: Unix Shell

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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