Malicious .git Configs Can Make Claude, Codex, Cursor, and Other AI Agents Run Attacker Code
Malicious .git core.fsmonitor configs let attacker code run in AI coding agents like Claude Code and Codex; four of eight flaws remain unpatched.
Manifold Security disclosed eight flaws across seven command-line AI coding agents where a repository's Git core.fsmonitor configuration causes agent-spawned commands to execute attacker code outside the sandbox and without approval prompts. Fixes shipped for goose (CVE-2026-72718, CVSS 4.0 score 7.0), Claude Code on one path, and Cursor, while Hermes Agent, Qwen Code, Grok Build, and a second Claude Code path were still unpatched as of September 1. OpenAI issued three CVEs for the same class in Codex, including CVE-2026-19592, and prior related bugs include CVE-2021-43891 in Visual Studio Code and CVE-2022-24346 in JetBrains IDEs. Exploitation requires the repository to arrive with its .git directory intact, such as via archives, shared drives, or USB sticks rather than an ordinary clone.
GitHub Pays $100,000 Bounty for Critical RCE Flaw in Git Push Pipeline
GitHub paid Saif Ghani $100,000 for CVE-2026-3854, a critical unauthenticated RCE in its Git push pipeline allowing command execution on backend infrastructure.
GitHub awarded researcher Saif Ghani $100,000, its largest publicly disclosed bug bounty, for CVE-2026-3854, a critical unauthenticated remote code execution flaw in its Git push processing pipeline. A crafted repository URL could trigger arbitrary command execution on backend infrastructure, threatening source code integrity, repository secrets, and software supply chains. GitHub deployed mitigations and completed a patch rollout through coordinated disclosure before technical details became public.
Agents Gone Wild: An AI-Orchestrated Global Campaign Against PaperCut NG/MF
AI-orchestrated campaign exploited PaperCut NG/MF RCE (CVE-2026-81578/82078), compromising 440+ instances at 395 organizations in 48 countries.
GreyNoise tracked a likely Russian-speaking actor using AI (OpenAI Codex harness plus a DeepSeek model) to develop, test, and deploy exploits for PaperCut NG/MF (CVE-2026-81578, CVE-2026-82078) starting 31 August 2026. The actor compromised at least 440 PaperCut instances across 395 organizations in 48 countries, achieving domain admin at 12 victims — fastest time to domain admin was five minutes and a US high school was fully compromised in seven minutes. Attack paths involved LSASS memory and registry secret harvesting, pass-the-hash to domain controllers, noPac attacks, account additions to Domain Admins, and DCSync to exfiltrate full NTDS.DIT credential dumps. Impact scope suggests access development potentially for handoff, with prior PaperCut intrusions historically leading to extortion.
The VMs Powering Mobile Agents (Instinct, Claude Code)
A teardown reveals Claude Code runs in Firecracker microVMs with a Rust PID 1 and MITM'd egress, while Instinct rents E2B sandboxes with git-based memory.
The author inspects the virtual machines hosting cloud agents: Claude Code runs in a Firecracker microVM with a custom Rust init (process_api) as PID 1, a 324 MB Bun harness on a read-only disk, and 443-only MITM'd SSE egress to api.anthropic.com with host-rotated OAuth tokens and no inbound access. Instinct rents E2B sandbox-as-a-service Firecracker microVMs (Ubuntu 22.04, 2 vCPU, 1.9 GB RAM) where agent memory is a git repo of Markdown committed by the agent and pushed to S3 as a single bundle, using short-lived STS credentials. Both platforms rely on Firecracker, differing mainly in fleet operator and guest boot configuration.
Emerging Threat: (CVE-2026-60004) Gitea Remote Code Execution via ...
CVE-2026-60004 (CVSS 9.8) lets attackers with repository write access achieve RCE on self-hosted Gitea servers via malicious git hooks; fixed in 1.27.1.
CVE-2026-60004 is a CWE-94 code injection flaw in Gitea's POST /api/v1/repos/{owner}/{repo}/diffpatch endpoint, disclosed July 28, 2026 with a CVSS v3.1 score of 9.8 and credited to researcher Shai Rod (NightRang3r). An add/add collision with the three-way merge fallback (--3, Git 2.32+) writes attacker-controlled content into the temporary bare clone's hooks directory, where it executes as a live Git hook running commands as the Gitea OS user. Exploitation requires repository write access, but Gitea's default open registration allows anonymous users to obtain it, exposing app.ini secrets, database credentials, OAuth tokens, and mounted repositories; a public PoC requires no outbound callback. All releases from 1.17 through 1.27.0 are affected; the fix shipped in Gitea 1.27.1 on July 27, 2026, and Gitea Cloud instances were upgraded automatically.