# CVE-2026-5917: libgit2 Shell Command Injection via ssh_libssh2 Backend

> Remote attackers can execute arbitrary commands on SSH servers via malicious repository paths in libgit2 when using the libssh2 backend.

- **Severity:** High 8.6 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 11 Aug 2026
- **Updated:** 1 Oct 2026
- **Also known as:** BELL-CVE-2026-5917, DEBIAN-CVE-2026-5917, ECHO-25c0-43ef-f653, GHSA-3gwr-xcwq-7892, GHSA-xqj4-2j5v-rr75, JLSEC-2026-1275, OESA-2026-4621, OESA-2026-4622, OESA-2026-4623, UBUNTU-CVE-2026-5917, USN-8809-1, openSUSE-SU-2026:11521-1

## What is CVE-2026-5917?

CVE-2026-5917 is a high-severity command injection vulnerability in libgit2, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-5917?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libgit2` | openSUSE:Tumbleweed | All versions | 1.9.7-1.1 |

## How do I fix CVE-2026-5917?

Upgrade to a fixed version.

## Is CVE-2026-5917 being exploited?

There is no known exploitation of CVE-2026-5917 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5917 and fix it if it is affected.

What it is: CVE-2026-5917 is a high-severity command injection vulnerability in libgit2, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-5917 in the wild and no public exploit code.

Affected product: libgit2. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-5917/ (Markdown: https://insights.sbomify.com/CVE-2026-5917/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5917
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5917
- OSV: https://osv.dev/vulnerability/CVE-2026-5917

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5917/
Summaries are generated and may contain mistakes; the official description above is the record.