BREW-AIDER-CVE-2026-73625 (GHSA-R9MR-M37C-5FR3)
Vulnerability from osv_homebrew – Published: 2026-08-14 08:50 – Updated: 2026-10-08 00:29 – Source websiteSummary
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@3.1.46",
"upstream_fixed_in": "3.1.54"
},
"package": {
"ecosystem": "Homebrew",
"name": "aider",
"purl": "pkg:brew/aider"
},
"ranges": [
{
"events": [
{
"introduced": "0.47.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"database_specific": {
"confidence": "high",
"source": "matched",
"strategy": "registry",
"upstream_evidence": [
{
"ecosystem": "PyPI",
"key": "pkg:pypi/gitpython@3.1.46",
"name": "gitpython",
"resource": "gitpython",
"strategy": "registry",
"subject_version": "3.1.46"
}
]
},
"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-aider-CVE-2026-73625",
"modified": "2026-10-08T00:29:13Z",
"published": "2026-08-14T08:50:09Z",
"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"
]
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.