brew-cobo-cli-cve-2026-73625
Vulnerability from osv_homebrew
Summary
GitPython's check_unsafe_options guard (the control introduced by CVE-2026-42215 / GHSA-2f96 and hardened since) can be bypassed for every guarded method (clone/clone_from, fetch/pull/push, ls_remote, iter_commits, blame, archive) by smuggling an option token inside the VALUE of a single-character kwarg. In the default allow_unsafe_options=False configuration this yields arbitrary command execution via --upload-pack.
Root Cause
The guard builds its candidate option list from kwarg KEYS only: _option_candidates([], {"n":"--upload-pack=<cmd>"}) returns ['-n'] (cmd.py:1042-1046 derives the candidate from the key, never the value). -n is not on the denylist, so check_unsafe_options passes. But transform_kwarg('n', value, split_single_char_options=True) (cmd.py:1600-1606) emits two argv tokens ['-n', '--upload-pack=<cmd>']. git then parses the second token as --upload-pack and executes the attacker-supplied command. The guard never inspects the value that becomes a separate argv token.
Impact
Arbitrary OS command execution as the host process (via --upload-pack) in the default configuration, affecting all guarded methods since they all build candidates through the name-only _option_candidates.
Proof of Concept
from git import Repo
Repo.clone_from(bare_repo, out_dir, n="--upload-pack=touch /tmp/ACE;git-upload-pack")
# /tmp/ACE created -> ACE. Direct-name form upload_pack="..." is correctly BLOCKED.
File-write variant on a guarded revision command: iter_commits('HEAD', g='--output=/path') -> candidate ['-g'] passes, argv ['-g','--output=/path'], victim file truncated.
Attack Chain
- Entry: app forwards a user-supplied options dict ->
Repo.clone_from(url, path, n="--upload-pack=touch /tmp/ACE;git-upload-pack"). Guard:check_unsafe_options(options=_option_candidates([], kwargs), unsafe=unsafe_git_clone_options)at base.py. Bypass proof:_option_candidates([], {"n":"--upload-pack=..."})->['-n'](key-only), not on denylist -> no UnsafeOptionError (verified live). - Transform:
transform_kwarg('n', value, split_single_char_options=True)->['-n', '--upload-pack=touch /tmp/ACE;git-upload-pack']. Guard: none (guard already passed on name-only candidate). Bypass proof: verified transform emits two tokens. - Sink:
git clone -n --upload-pack='touch ...;git-upload-pack' -- <src> <dst>; git parses and runs the second token. Impact: ACE (marker created, verified end-to-end).
Bypass Evidence
Live-verified on HEAD (tag 3.1.53): _option_candidates returns key-only candidate ['-n']; transform_kwargs emits the smuggled --upload-pack= token; clone_from with the payload created the marker file; the direct-name upload_pack= form raised UnsafeOptionError. All prior bypasses (GHSA-rpm5 underscore key, GHSA-2f96 long-option abbreviation, GHSA-v396 joined short option, GHSA-x2qx multi-before-split) are BLOCKED on HEAD — this is a distinct kwarg-value->separate-token vector.
Affected Versions
<= 3.1.53
Suggested Fix
Make _option_candidates also emit candidates derived from single-character kwarg VALUES when split_single_char_options is in effect, OR run check_unsafe_options over the fully-transformed argv rather than the reconstructed name-only candidate list.
Reported by zx (Jace) — GitHub: @manus-use
{
"affected": [
{
"ecosystem_specific": {
"fix": null,
"range_state": "affected",
"resource": "gitpython",
"resource_purl": "pkg:pypi/gitpython@3.1.50",
"upstream_fixed_in": "3.1.54"
},
"package": {
"ecosystem": "Homebrew",
"name": "cobo-cli",
"purl": "pkg:brew/cobo-cli"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.1.8_7"
},
{
"introduced": "0.1.10"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"database_specific": {
"confidence": "high",
"source": "matched",
"strategy": "registry",
"upstream_evidence": [
{
"ecosystem": "PyPI",
"key": "pkg:pypi/gitpython@3.1.50",
"name": "gitpython",
"resource": "gitpython",
"strategy": "registry",
"subject_version": "3.1.50"
}
]
},
"details": "## Summary\nGitPython\u0027s `check_unsafe_options` guard (the control introduced by CVE-2026-42215 / GHSA-2f96 and hardened since) can be bypassed for **every** guarded method (`clone`/`clone_from`, `fetch`/`pull`/`push`, `ls_remote`, `iter_commits`, `blame`, `archive`) by smuggling an option token inside the VALUE of a single-character kwarg. In the default `allow_unsafe_options=False` configuration this yields arbitrary command execution via `--upload-pack`.\n\n## Root Cause\nThe guard builds its candidate option list from kwarg KEYS only: `_option_candidates([], {\"n\":\"--upload-pack=\u003ccmd\u003e\"})` returns `[\u0027-n\u0027]` (cmd.py:1042-1046 derives the candidate from the key, never the value). `-n` is not on the denylist, so `check_unsafe_options` passes. But `transform_kwarg(\u0027n\u0027, value, split_single_char_options=True)` (cmd.py:1600-1606) emits **two** argv tokens `[\u0027-n\u0027, \u0027--upload-pack=\u003ccmd\u003e\u0027]`. git then parses the second token as `--upload-pack` and executes the attacker-supplied command. The guard never inspects the value that becomes a separate argv token.\n\n## Impact\nArbitrary OS command execution as the host process (via `--upload-pack`) in the default configuration, affecting all guarded methods since they all build candidates through the name-only `_option_candidates`.\n\n## Proof of Concept\n```python\nfrom git import Repo\nRepo.clone_from(bare_repo, out_dir, n=\"--upload-pack=touch /tmp/ACE;git-upload-pack\")\n# /tmp/ACE created -\u003e ACE. Direct-name form upload_pack=\"...\" is correctly BLOCKED.\n```\nFile-write variant on a guarded revision command: `iter_commits(\u0027HEAD\u0027, g=\u0027--output=/path\u0027)` -\u003e candidate `[\u0027-g\u0027]` passes, argv `[\u0027-g\u0027,\u0027--output=/path\u0027]`, victim file truncated.\n\n## Attack Chain\n1. Entry: app forwards a user-supplied options dict -\u003e `Repo.clone_from(url, path, n=\"--upload-pack=touch /tmp/ACE;git-upload-pack\")`. Guard: `check_unsafe_options(options=_option_candidates([], kwargs), unsafe=unsafe_git_clone_options)` at base.py. Bypass proof: `_option_candidates([], {\"n\":\"--upload-pack=...\"})` -\u003e `[\u0027-n\u0027]` (key-only), not on denylist -\u003e no UnsafeOptionError (verified live).\n2. Transform: `transform_kwarg(\u0027n\u0027, value, split_single_char_options=True)` -\u003e `[\u0027-n\u0027, \u0027--upload-pack=touch /tmp/ACE;git-upload-pack\u0027]`. Guard: none (guard already passed on name-only candidate). Bypass proof: verified transform emits two tokens.\n3. Sink: `git clone -n --upload-pack=\u0027touch ...;git-upload-pack\u0027 -- \u003csrc\u003e \u003cdst\u003e`; git parses and runs the second token. Impact: ACE (marker created, verified end-to-end).\n\n## Bypass Evidence\nLive-verified on HEAD (tag 3.1.53): `_option_candidates` returns key-only candidate `[\u0027-n\u0027]`; `transform_kwargs` emits the smuggled `--upload-pack=` token; clone_from with the payload created the marker file; the direct-name `upload_pack=` form raised UnsafeOptionError. All prior bypasses (GHSA-rpm5 underscore key, GHSA-2f96 long-option abbreviation, GHSA-v396 joined short option, GHSA-x2qx multi-before-split) are BLOCKED on HEAD \u2014 this is a distinct kwarg-value-\u003eseparate-token vector.\n\n## Affected Versions\n`\u003c= 3.1.53`\n\n## Suggested Fix\nMake `_option_candidates` also emit candidates derived from single-character kwarg VALUES when `split_single_char_options` is in effect, OR run `check_unsafe_options` over the fully-transformed argv rather than the reconstructed name-only candidate list.\n\n---\nReported by **zx (Jace)** \u2014 GitHub: @manus-use",
"id": "BREW-cobo-cli-CVE-2026-73625",
"modified": "2026-09-10T19:01:17Z",
"published": "2026-08-14T08:54:44Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/security/advisories/GHSA-r9mr-m37c-5fr3"
},
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/pull/2180"
},
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/commit/e8d0fbf774d1f6baa3b481adfe48bd262e43b453"
},
{
"type": "PACKAGE",
"url": "https://github.com/gitpython-developers/GitPython"
},
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/releases/tag/3.1.54"
}
],
"schema_version": "1.7.3",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "GitPython: Unsafe git option guard bypass via single-character kwarg value token smuggling enables arbitrary command execution",
"upstream": [
"GHSA-r9mr-m37c-5fr3",
"CVE-2026-73625",
"PYSEC-2026-3953"
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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