CVE-2026-35020: CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in Anthropic Claude Code
Anthropic Claude Code CLI and Claude Agent SDK contain an OS command injection vulnerability in the command lookup helper and deep-link terminal launcher that allows local attackers to execute arbitrary commands by manipulating the TERMINAL environment variable. Attackers can inject shell metacharacters into the TERMINAL variable which are interpreted by /bin/sh when the command lookup helper constructs and executes shell commands with shell=true. The vulnerability can be triggered during normal CLI execution as well as via the deep-link handler path, resulting in arbitrary command execution with the privileges of the user running the CLI.
AI Analysis
Technical Summary
CVE-2026-35020 is an OS command injection vulnerability in Anthropic Claude Code CLI and Claude Agent SDK. It arises from improper neutralization of special elements in the TERMINAL environment variable, which is used by a command lookup helper and deep-link terminal launcher. Attackers can manipulate this variable to inject shell metacharacters, which are interpreted by /bin/sh when commands are constructed and executed with shell=true. This leads to arbitrary command execution with the privileges of the user running the CLI. The vulnerability can be triggered during normal CLI execution or via the deep-link handler path.
Potential Impact
Successful exploitation allows local attackers to execute arbitrary OS commands with the privileges of the user running the Anthropic Claude Code CLI or Agent SDK. This can lead to unauthorized actions on the affected system, potentially compromising system integrity and confidentiality. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, avoid running the affected CLI or SDK in untrusted environments and do not set or allow untrusted control over the TERMINAL environment variable. Monitor vendor channels for updates.
CVE-2026-35020: CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in Anthropic Claude Code
Description
Anthropic Claude Code CLI and Claude Agent SDK contain an OS command injection vulnerability in the command lookup helper and deep-link terminal launcher that allows local attackers to execute arbitrary commands by manipulating the TERMINAL environment variable. Attackers can inject shell metacharacters into the TERMINAL variable which are interpreted by /bin/sh when the command lookup helper constructs and executes shell commands with shell=true. The vulnerability can be triggered during normal CLI execution as well as via the deep-link handler path, resulting in arbitrary command execution with the privileges of the user running the CLI.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-35020 is an OS command injection vulnerability in Anthropic Claude Code CLI and Claude Agent SDK. It arises from improper neutralization of special elements in the TERMINAL environment variable, which is used by a command lookup helper and deep-link terminal launcher. Attackers can manipulate this variable to inject shell metacharacters, which are interpreted by /bin/sh when commands are constructed and executed with shell=true. This leads to arbitrary command execution with the privileges of the user running the CLI. The vulnerability can be triggered during normal CLI execution or via the deep-link handler path.
Potential Impact
Successful exploitation allows local attackers to execute arbitrary OS commands with the privileges of the user running the Anthropic Claude Code CLI or Agent SDK. This can lead to unauthorized actions on the affected system, potentially compromising system integrity and confidentiality. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, avoid running the affected CLI or SDK in untrusted environments and do not set or allow untrusted control over the TERMINAL environment variable. Monitor vendor channels for updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-03-31T20:40:15.618Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d409d70a160ebd92d5a92f
Added to database: 4/6/2026, 7:30:31 PM
Last enriched: 4/14/2026, 11:23:37 AM
Last updated: 5/21/2026, 11:01:43 PM
Views: 70
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