Full Report
Manifold Security has disclosed eight security flaws across seven command-line AI coding agents in which a repository's own Git configuration names a command that the agent runs on the developer's machine, four of them still unpatched at publication. The command executes as the user, outside the agent's sandbox and without an approval prompt, and exploitation requires the repository to arrive
Analysis Summary
# Morning News Roll-up September 02, 2026
## Overview
Today's report highlights a significant class of vulnerabilities discovered by Manifold Security, dubbed "GitSpawn." These flaws affect several high-profile AI coding agents, allowing for arbitrary code execution through malicious Git configurations. Additionally, we cover updates on specific CVEs released by OpenAI and historical context regarding similar bypasses in popular IDEs.
## Top Stories
### Malicious .git Configs Enable Code Execution in AI Agents
- Summary: Manifold Security disclosed eight flaws across seven AI coding agents where a repository's internal Git configuration (specifically `core.fsmonitor`) can trigger unprompted command execution on a developer's machine. The attack bypasses sandboxes and trust prompts, running with the user's full privileges. While some agents like Claude Code and Cursor have issued patches, several remain vulnerable.
- Source: hxxps://thehackernews[.]com/2026/09/malicious-git-configs-can-make-claude.html
### OpenAI Addresses Codex CLI and Desktop Vulnerabilities
- Summary: OpenAI published three CVEs (including CVE-2026-19592) regarding its Codex line of products. The vulnerabilities allow attacker-controlled code to run outside the command sandbox, potentially leading to the theft or deletion of user files. These findings were credited to three independent research groups.
- Source: hxxps://thehackernews[.]com/2026/09/malicious-git-configs-can-make-claude.html
### Recursive Vulnerabilities: The Persistent Challenge of "Pre-Trust" Execution
- Summary: Analysis reveals that AI agents are falling victim to the same "plumbing" issues that previously affected major IDEs like VS Code and JetBrains. Despite previous attempts by developers like Anthropic to mitigate these risks, new research shows that "pre-trust" execution paths (where code runs before a user clicks 'Approve') continue to resurface in updated versions of AI tools.
- Source: hxxps://thehackernews[.]com/2026/09/malicious-git-configs-can-make-claude.html
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# GitSpawn: AI Coding Agent Hijack via Git Configuration
## Key Points
- **Nature of the Flaw**: The vulnerability, dubbed **GitSpawn**, exploits how AI agents invoke Git subprocesses upon entering a directory.
- **The Mechanism**: Agents read the `.git/config` file from a local repository. If the `core.fsmonitor` setting is defined, Git executes the specified command to track file changes.
- **Bypassing Protections**: Commands execute outside the agent’s sandbox, before model calls, and often before "Workspace Trust" prompts are displayed to the user.
- **Delivery Vector**: Exploitation requires the victim to download/access a repository where the `.git` directory is intact (e.g., via a ZIP archive, shared drive, or USB). Standard `git clone` operations typically do not preserve the attacker's local `.git/config`, making manual distribution of the folder the primary vector.
- **Unpatched Status**: As of September 1, 2026, four of the identified agents remained unpatched.
## Threat Actors
- **Attribution**: No specific malicious campaigns or threat actors are currently identified as actively exploiting these in the wild; however, the research was conducted and disclosed by **Manifold Security**.
- **Motivation**: Potential attackers would likely be motivated by intellectual property theft, credential harvesting, or gaining a foothold in developer environments (Supply Chain attacks).
## TTPs
- **Command Injection via Configuration**: Exploiting the `core.fsmonitor` Git performance setting.
- **Execution Flow**:
1. Victim opens a malicious repository in an AI-powered CLI or IDE.
2. The agent automatically runs `git status` or `git diff` to gather context.
3. The malicious command in `.git/config` executes with user privileges.
- **MITRE ATT&CK References**:
- **T1059.007**: Command and Scripting Interpreter: JavaScript (for Node-based agents).
- **T1546.012**: Event Triggered Execution: Sentinel Files (Abusing Git config).
- **T1204.002**: User Execution: Malicious File.
## Affected Systems
- **goose**: Versions < 1.44.0 (Fixed in 1.44.0; CVE-2026-72718).
- **Codex CLI/Desktop**: Various versions (Fixed in 0.131.0 and recent Desktop builds; CVE-2026-19592).
- **Claude Code**: Fixed on `core.fsmonitor` path (v2.1.196), but other paths (`claude ultrareview`) were reported live in v2.1.252.
- **Hermes Agent**: v0.18.2 and v0.21.0 (Fix pending).
- **Qwen Code**: v0.19.6 and v0.22.3 (Fix pending).
- **Grok Build**: v0.2.93 and 1.0.13 (Fix pending).
- **Cursor**: Reported as fixed.
## Mitigations
- **Update Software**: Immediately update AI coding agents (goose, Claude Code, Codex, Cursor) to the latest available versions.
- **Sanitize Git Invocations**: Developers of AI agents should use the `-c core.fsmonitor=` flag when spawning Git subprocesses to override local repository configurations.
- **Caution with Archives**: Avoid opening repository folders or archives from untrusted sources, especially those containing hidden `.git` directories.
- **Environment Isolation**: Run AI coding agents within restricted containers or virtual machines when interacting with third-party code.
## Conclusion
The GitSpawn findings demonstrate that the "plumbing" of developer tools remains a significant attack surface. Even as AI agents implement sophisticated model-level safety, they remain vulnerable to classic configuration-based exploits. Developers and organizations should prioritize updating their AI CLI tools and exercise extreme caution when downloading and interacting with pre-packaged code repositories.