Description

GitPython before 3.1.54 contains an incomplete denylist in unsafe_git_clone_options that omits --template, allowing attackers to achieve arbitrary command execution during clone operations. Attackers can supply --template pointing to a directory containing malicious post-checkout hooks that execute when git clones the repository.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-13T12:17:27.477Z",
  "pubdate": "2026-08-13T12:17:27.477Z",
  "executiveSummary": "GitPython before version 3.1.54 contains an incomplete denylist vulnerability within the unsafe_git_clone_options mechanism.\nThe vulnerability allows remote attackers to achieve arbitrary command execution during repository clone operations.\nThe affected product is GitPython in versions prior to 3.1.54.\nRisk implications include full system compromise or execution of arbitrary code in the context of the user running the clone operation.\nAttacker capabilities involve supplying malicious arguments, specifically the omitted --template option, to target clone procedures.\nExploitation requires the attacker to trick a user or application into cloning a repository with maliciously crafted clone options that leverage template injection.",
  "technicalDetails": "The root cause of the vulnerability resides in an incomplete denylist implementation inside the unsafe_git_clone_options component of GitPython.\nWhile certain potentially dangerous command-line options for the underlying git executable are restricted or filtered, the denylist specifically omits the --template parameter.\nThe vulnerable component is the argument validation logic used when passing parameters to git clone operations within GitPython prior to version 3.1.54.\nNo authentication or specific privilege requirements are inherently mandated by the vulnerability itself; rather, exploitation relies on the application's handling of untrusted input passed to clone functions.\nThe network exposure depends on how the application utilizes GitPython to process repositories from remote or untrusted sources.\nThe exploitation method begins when an attacker supplies a malicious command-line option, specifically --template, pointing to a local or externally accessible directory containing crafted template files.\nDuring the execution of git clone, Git honors the --template option by copying files from the specified template directory into the new repository's .git directory.\nAn attacker leverages this behavior by populating the template directory with a malicious post-checkout hook script.\nAs the clone operation completes and the working tree is populated, git automatically executes the post-checkout hook located within the .git/hooks directory.\nThe payload behavior involves the immediate execution of arbitrary operating system commands defined in the post-checkout hook script, executing within the security context of the user process invoking GitPython.\nThe post-exploitation impact includes arbitrary command execution, potential lateral movement, data exfiltration, or complete compromise of the host environment depending on the privileges of the executing process."
}