CVE-2026-5917
CriticalCVSS 9.6Summary
libgit2 versions v0.27.0 through v1.9.0 built with the libssh2 SSH backend contain a shell command injection vulnerability that allows remote attackers to execute arbitrary commands on an SSH server by supplying a repository path containing unescaped shell metacharacters. The gen_proto() function in ssh_libssh2.c inserts the repository path directly into a shell command string without escaping special characters before passing it to libssh2_channel_exec(), enabling an attacker to craft a malicious submodule URL in a .gitmodules file that, when processed during a recursive clone, causes the remote server's shell to interpret injected commands under the victim's SSH user account.
Risk Assessment
An attacker could execute arbitrary commands on the SSH server in the context of the victim's user, potentially leading to system compromise and security breach.
Recommendation
Upgrade libgit2 to a version newer than 1.9.0 or apply vendor patches, and avoid cloning untrusted repositories.
Original NVD description (English source)
libgit2 versions v0.27.0 through v1.9.0 built with the libssh2 SSH backend (USE_SSH=libssh2) contain a shell command injection vulnerability that allows remote attackers to execute arbitrary commands on an SSH server by supplying a repository path containing unescaped shell metacharacters such as single quotes, semicolons, or pipes. The gen_proto() function in ssh_libssh2.c inserts the repository path directly into a shell command string without escaping special characters before passing it to libssh2_channel_exec(), enabling an attacker to craft a malicious submodule URL in a .gitmodules file that, when processed during a recursive clone, causes the remote server's shell to interpret injected commands under the victim's SSH user account.