{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.1.53"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "GitPython"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.54"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-88"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T16:41:20Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Summary\n`Diffable.diff()` forwards `**kwargs` straight into `diff`/`diff_tree` with **no** `check_unsafe_options` guard. `Diffable` is mixed into `Commit`, `Tree`, `IndexFile`, and `Submodule`, giving a broad surface. `git diff --output=\u003cpath\u003e` writes real patch content to an attacker-chosen path, enabling arbitrary file overwrite.\n\n## Root Cause\n`diff.py:188-283` builds and runs the diff command with no `check_unsafe_options` anywhere in the method (grep-confirmed). Additionally `diff.py:265` does `args.insert(0, other)`, placing the caller-supplied `other` ref BEFORE the `--` separator, so a value of `--output=/path` is parsed by git as an option \u2014 a value-only control path requiring no kwarg key.\n\n## Impact\nOverwrite/corrupt any file at process privilege with attacker-chosen path (e.g. `~/.ssh/authorized_keys`, configs, lockfiles). Content is real diff/patch bytes (attacker-influenced). Per the skill\u0027s rule, controlling WHICH file is overwritten = I:H regardless of content constraints.\n\n## Proof of Concept\n```python\n# Key-control:\ncommit.diff(other_commit, output=\u0027/home/app/.ssh/authorized_keys\u0027)   # victim overwritten with diff (105 bytes verified)\n# Value-control (attacker controls only the ref string):\ncommit.diff(other=\u0027--output=/home/app/.ssh/authorized_keys\u0027)          # 14-byte victim -\u003e 146 bytes of diff-tree output\n```\n\n## Attack Chain\n1. Entry (value-control): `commit.diff(other=\u003cuser ref\u003e)` with `other = \"--output=/home/app/.ssh/authorized_keys\"`. Guard: none in `Diffable.diff`. Bypass proof: no `check_unsafe_options` in the method body (grep); `other` inserted pre-`--` at diff.py:265.\n2. Sink: `git diff-tree \u003csha\u003e --output=/home/app/.ssh/authorized_keys -r ...` -\u003e git opens+truncates the target then writes diff content. Impact: overwrite/corrupt any file at process privilege (attacker chooses the path). Verified argv and victim overwrite live.\n\n## Bypass Evidence\nLive-verified on HEAD (tag 3.1.53): both key-control (`output=`) and value-control (`other=\u0027--output=...\u0027`) overwrote a victim file with real diff-tree content; argv confirmed `[\u0027git\u0027,\u0027diff-tree\u0027,\u0027\u003csha\u003e\u0027,\u0027--output=/victim\u0027,\u0027-r\u0027,...]`. This is the same value-control model GHSA-956x deemed fix-worthy for `iter_commits(rev=\u0027--output=\u0027)` \u2014 but `diff` is a distinct, unguarded sink NOT touched by that fix.\n\n## Affected Versions\n`\u003c= 3.1.53`\n\n## Suggested Fix\nAdd `check_unsafe_options` to `Diffable.diff` (mirroring `iter_commits`/`archive`), and/or place `--end-of-options` before the `other` ref so it cannot be parsed as an option.\n\n---\nReported by **zx (Jace)** \u2014 GitHub: @manus-use",
  "id": "GHSA-fjr4-x663-mwxc",
  "modified": "2026-07-24T16:41:21Z",
  "published": "2026-07-24T16:41:20Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/gitpython-developers/GitPython/security/advisories/GHSA-fjr4-x663-mwxc"
    },
    {
      "type": "WEB",
      "url": "https://github.com/gitpython-developers/GitPython/pull/2180"
    },
    {
      "type": "WEB",
      "url": "https://github.com/gitpython-developers/GitPython/commit/1d51b891d7f236044a6aa17498ec682b63dad6e6"
    },
    {
      "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": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "GitPython: Arbitrary file overwrite via git diff --output argument injection in Diffable.diff (key- and value-controlled)"
}