Vulnerability · Published May 13, 2026 · Assigned by GitHub_M

CVE-2026-45033GitHub Copilot CLI: Nested Bare Repository Can Execute Arbitrary Commands via core.fsmonitor

High 8.5

In plain English

A high-severity security flaw in copilot-cli from github. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.5High

Exploit odds (30 days)0.4%top 71.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack tooling1Public PoC

Official description

GitHub Copilot CLI brings AI-powered coding assistance directly to your command line. Prior to 1.0.43, 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. 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. This vulnerability is fixed in 1.0.43.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@github/copilot	1.0.43	GHSA-9ccr-r5hg-74gf

Affected products (as reported)

Vendor	Product	Versions
github	copilot-cli	< 1.0.43

Weakness: CWE-696 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References

https://github.com/github/copilot-cli/security/advisories/GHSA-9ccr-r5hg-74gf x_refsource_CONFIRM