# CVE-2026-45033: @github/copilot RCE β€” Fixed in 1.0.43 πŸ“¦ npm Not in CISA KEV # CVE-2026-45033 β€” @github/copilot CVE-2026-45033 is a CWE-696 vulnerability in @github/copilot. A fix is available for @github/copilot β€” see the affected versions and patch details below. GitHub Copilot CLI: Nested Bare Repository Can Execute Arbitrary Commands via core.fsmonitor Also known as[GHSA-9ccr-r5hg-74gf](/vulnerability/GHSA-9ccr-r5hg-74gf) Published May 13, 2026 Updated Oct 28, 2026 Affected 1 pkg Patched 1 / 1 Exploits None indexed Exploitation data as of Nov 10, 2026 Β· OSV.dev, NVD, FIRST.org (EPSS) ## Exploitation Status ### Proof-of-concept exploit code exists - CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation. - A successful exploit gives an attacker total control of the affected component, not partial access. Exploitation and automatability from CISA’s SSVC triage for CVE-2026-45033. ## EPSS Exploitation Probability [via FIRST.org β†—](https://www.first.org/epss/) 0.4%probability of exploitation in next 30 days Lower Risk0.00% Lower risk than most CVEs29th percentile β€” riskier than 29% of all scored CVEsHighest risk 0.00%0.29%0.59%0.88%0.0%0.4%Jun 26Sep 26Nov 26 Probability of exploitation in the next 30 days, from [FIRST.org EPSS](https://www.first.org/epss/). ## Real-World Exposure 1 pkg affected How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched. 24other npm packages depend on this β€” each one inherits the vulnerability until it's patched upstream `@github/copilot`npm 1.9Mdownloads / week ## Description ### Summary A security vulnerability has been identified in GitHub Copilot CLI where a malicious bare git repository nested inside a project directory can achieve arbitrary code execution when the agent performs git operations. By exploiting git's automatic bare repository discovery during directory traversal, an attacker can set `core.fsmonitor` or other executable config keys to run arbitrary commands without user awareness or approval. ### Details Git supports bare repositories β€” repositories without a working tree β€” which can be discovered automatically when git traverses the directory hierarchy looking for a `.git` directory. When git discovers a bare repository, it reads and applies its configuration, including keys that specify external commands to execute. The vulnerability arises because git's `core.fsmonitor` config key (and 15+ similar keys such as `core.hookspath`, `diff.external`, `merge.tool`, etc.) can specify arbitrary shell commands that git will execute as part of normal operations like `status`, `diff`, or `rev-parse`. #### Attack Scenario An attacker can exploit this by: 1. Creating a bare git repository nested inside a seemingly normal project directory (e.g., `vendor/malicious.git/` or a deeply nested subdirectory) 2. Configuring `core.fsmonitor` (or similar keys) in that bare repository to execute a malicious command 3. When GitHub Copilot CLI performs any git operation that traverses into or through that directory, git auto-discovers the bare repository, reads its config, and executes the attacker's command This can occur when: - The agent navigates into a subdirectory containing the buried bare repo - The agent runs `git status`, `git diff`, or other routine git commands - The agent uses tools like `grep` or `glob` that may trigger git operations in subdirectories Prior to the fix, the CLI had no protection against git auto-discovering bare repositories during directory traversal. ### Impact An attacker who can place a malicious bare repository inside a project β€” for example, through: - A pull request adding a directory that contains a bare repository - A compromised or malicious dependency that includes a bare repository - A cloned repository that already contains nested bare repositories β€” could achieve arbitrary code execution on the user's workstation whenever GitHub Copilot CLI performs git operations in or near the malicious directory. Successful exploitation could lead to data exfiltration, credential theft, file modification, or further system compromise. ### Affected Versions - GitHub Copilot CLI versions prior to 1.0.42 ### Remediation and Mitigation #### Fix The fix sets `safe.bareRepository=explicit` via git's `GIT_CONFIG_COUNT` / `GIT_CONFIG_KEY_*` / `GIT_CONFIG_VALUE_*` environment variable mechanism, which has the highest precedence over all config file sources. This prevents git from automatically discovering and using bare repositories during directory traversal β€” only explicitly allowlisted bare repositories will be used. #### User Actions 1. **Upgrade** GitHub Copilot CLI to **1.0.43** or later. 2. **Exercise caution** when working in repositories that contain nested bare git repositories. 3. **Review** project directories for unexpected bare repositories, especially in `vendor/`, `third_party/`, or deeply nested subdirectories. ## Affected Packages 1 total 1 fixed Ecosystem Package Vulnerable range Fix πŸ“¦npm `@github/copilot` all versions 1.0.43`npm install @github/copilot@1.0.43` ## Affected Products 1 product Β· 1 configurations Application `copilot-cli`github < 1.0.43 range ## Detection & mitigation playbook Open-source dependency 1. ### Detect Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @github/copilot, including transitive dependencies β€” a direct dependency you never call can still pull in a vulnerable version. 2. ### Fix Update @github/copilot to 1.0.43 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range β€” O3 confirms CVE-2026-45033 is resolved across your whole dependency graph. 3. ### Workarounds Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves. ## Frequently Asked Questions \## Summary A security vulnerability has been identified in GitHub Copilot CLI where a malicious bare git repository nested inside a project directory can achieve arbitrary code execution when the agent performs git operations. By exploiting git's automatic bare repository discovery during directory traversal, an attacker can set \`core.fsmonitor\` or other executable config keys to run arbitrary commands without user awareness or approval. ## Details Git supports bare repositories β€” repositories without a working tree β€” which can be discovered automatically when git traverses the directory hi O3 Security Β· Impact-Aware SCA ### Is CVE-2026-45033 in your dependencies? Find it across npm, including transitive dependencies. [Scan my dependencies](/book-demo) [How O3 SCA works](/impact-aware-sca)