{"id":"GHSA-65mp-fq8v-56jr","summary":"Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection","details":"### Impact\nA critical path traversal and extension bypass vulnerability in Flask-Reuploaded allows remote attackers to achieve arbitrary file write and remote code execution through Server-Side Template Injection (SSTI).\n\n### Patches\nFlask-Reuploaded has been patched in version 1.5.0\n\n### Workarounds\n\n1. **Do not pass user input to the `name` parameter**\n2. Use auto-generated filenames only\n3. Implement strict input validation if `name` must be used\n\n```python\nfrom werkzeug.utils import secure_filename\nimport os\n\n# Sanitize user input before passing to save()\nsafe_name = secure_filename(request.form.get('custom_name'))\n# Remove path separators\nsafe_name = os.path.basename(safe_name)\n# Validate extension matches policy\nif not photos.extension_allowed(photos.get_extension(safe_name)):\n    abort(400)\n    \nfilename = photos.save(file, name=safe_name)\n```\n\n### Resources\nThe fix is documented in the pull request, see https://github.com/jugmac00/flask-reuploaded/pull/180.\n\nA proper write-up was created by the reporter of the vulnerability, Jaron Cabral (https://www.linkedin.com/in/jaron-cabral-751994357/), but is not yet available as of time of this publication.","aliases":["CVE-2026-27641","PYSEC-2026-341"],"modified":"2026-06-29T12:26:48.788217782Z","published":"2026-02-25T19:06:50Z","database_specific":{"cwe_ids":["CWE-1336","CWE-22"],"severity":"CRITICAL","github_reviewed":true,"github_reviewed_at":"2026-02-25T19:06:50Z","nvd_published_at":"2026-02-25T04:16:04Z"},"references":[{"type":"WEB","url":"https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-65mp-fq8v-56jr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27641"},{"type":"WEB","url":"https://github.com/jugmac00/flask-reuploaded/pull/180"},{"type":"WEB","url":"https://github.com/jugmac00/flask-reuploaded/commit/d64c6b2f71cb73734fc38baa0e3e156926361288"},{"type":"PACKAGE","url":"https://github.com/jugmac00/flask-reuploaded"}],"affected":[{"package":{"name":"flask-reuploaded","ecosystem":"PyPI","purl":"pkg:pypi/flask-reuploaded"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.0"}]}],"versions":["0.3","0.3.1","0.3.2","0.4.0","0.5.0","1.0.0","1.1.0","1.2.0","1.3.0","1.4.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/02/GHSA-65mp-fq8v-56jr/GHSA-65mp-fq8v-56jr.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}