CVE-2026-12537Network attack vector

Pre-sandbox code execution via untrusted environment loading

Published Jun 24, 2026 · Updated Jun 24, 2026

OS command injection in Google Gemini CLI before 0.39.1 and run-gemini-cli before 0.1.22 allows remote attackers to execute code on CI hosts. In headless mode, automatic workspace trust loads an untrusted .gemini/.env file, and the container launcher processes its values without neutralizing shell metacharacters before starting the sandbox. A workflow must run Gemini CLI headlessly against attacker-controlled repository contents; successful exploitation executes commands on the runner host outside the sandbox.

CVSS severity10.0
Critical
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Google Gemini CLI before 0.39.1 and run-gemini-cli before 0.1.22 allows remote attackers to execute code on CI hosts. In headless mode, automatic workspace trust loads an untrusted .gemini/.env file, and the container launcher processes its values without neutralizing shell metacharacters before starting the sandbox. A workflow must run Gemini CLI headlessly against attacker-controlled repository contents; successful exploitation executes commands on the runner host outside the sandbox.

The record

CVE
CVE-2026-12537
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
Go standard library
Product
Gemini CLI
Classifications
CWE-78, CWE-20, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record 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=0 <0.39.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go standard library · Gemini CLIversion=0 <0.39.1
Go standard library · run-gemini-cliversion=0 <0.1.22

Published CVSS scores

10.0GoogleCloudCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
10.0GoogleCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-20Improper Input Validation
T1059Command and Scripting Interpreter

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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