libgit2 Shell Command Injection via ssh_libssh2 Backend (CVE-2026-5917) | HOL Guard CVE

Critical · CVSS 9.6CVE-2026-5917

libgit2 Shell Command Injection via ssh_libssh2 Backend

Answer in brief

CVE-2026-5917 records a Critical severity (CVSS 9.6) vulnerability in libgit2 Shell Command Injection via ssh_libssh2 Backend. The current sources do not mark it as known exploited. The current feed maps libgit2/libgit2 (generic), libgit2/libgit2 (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 11, 2026Updated Aug 26, 2026Source checked Aug 26, 2026First seen by HOL Aug 11, 2026Material review Aug 26, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.6
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 9.6. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps libgit2/libgit2 (generic), libgit2/libgit2 (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
libgit2/libgit2generic	0.27.0	Not reported
libgit2/libgit2generic	>=0 <1.8.7 \|\| >=1.9.0 <1.9.7	1.8.7, 1.9.7

Recommended response

Check inventory. Check lockfiles and deployed manifests for libgit2/libgit2, libgit2/libgit2.
Review the reported fix. Update libgit2/libgit2 to 1.8.7 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 26, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 11, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.