{"id":"CVE-2026-27641","aliases":["EUVD-2026-8616","GHSA-65mp-fq8v-56jr","PYSEC-2026-341"],"status":"published","title":"Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection","description":"Flask-Reuploaded provides file uploads for Flask. A critical path traversal and extension bypass vulnerability in versions prior to 1.5.0 allows remote attackers to achieve arbitrary file write and remote code execution through Server-Side Template Injection (SSTI). Flask-Reuploaded has been patched in version 1.5.0. Some workarounds are available. Do not pass user input to the `name` parameter, use auto-generated filenames only, and implement strict input validation if `name` must be used.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01337,"percentile":0.71464,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":true},"cwes":["CWE-1336","CWE-22"],"published":"2026-02-25T03:54:54Z","modified":"2026-10-28T02:30:27Z","exploits":[{"source":"pocgithub","id":"Max78000/CVE-2026-27641-Flask-Reuploaded","title":"Max78000/CVE-2026-27641-Flask-Reuploaded","date":"2026-07-23","url":"https://github.com/Max78000/CVE-2026-27641-Flask-Reuploaded"}],"fixes":[{"ecosystem":"PyPI","package":"flask-reuploaded","fixed_in":["1.5.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"flask-reuploaded","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"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"]},{"source":"osv","ecosystem":"PyPI","package":"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"]}],"products":[{"vendor":"jugmac00","product":"flask-reuploaded"}],"references":[{"url":"https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-65mp-fq8v-56jr","tags":["x_refsource_CONFIRM","Exploit","Vendor Advisory","advisory","web"]},{"url":"https://github.com/jugmac00/flask-reuploaded/pull/180","tags":["x_refsource_MISC","Issue Tracking","Patch","fix","web"]},{"url":"https://github.com/jugmac00/flask-reuploaded/commit/d64c6b2f71cb73734fc38baa0e3e156926361288","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27641","tags":["advisory"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/flask-reuploaded/PYSEC-2026-341.yaml","tags":["web"]},{"url":"https://pypi.org/project/flask-reuploaded","tags":["web","package"]},{"url":"https://github.com/advisories/GHSA-65mp-fq8v-56jr","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27641.json","tags":["advisory"]},{"url":"https://github.com/jugmac00/flask-reuploaded","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-27641","title":"Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection","description":"Flask-Reuploaded provides file uploads for Flask. A critical path traversal and extension bypass vulnerability in versions prior to 1.5.0 allows remote attackers to achieve arbitrary file write and remote code execution through Server-Side Template Injection (SSTI). Flask-Reuploaded has been patched in version 1.5.0. Some workarounds are available. Do not pass user input to the `name` parameter, use auto-generated filenames only, and implement strict input validation if `name` must be used.","status":"published","published":"2026-02-25T03:54:54.391Z","modified":"2026-02-25T21:12:45.608Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-1336"],"updated_at":"2026-11-02T14:19:48.826324Z"}],"euvd":[{"id":"EUVD-2026-8616","description":"Flask-Reuploaded provides file uploads for Flask. A critical path traversal and extension bypass vulnerability in versions prior to 1.5.0 allows remote attackers to achieve arbitrary file write and remote code execution through Server-Side Template Injection (SSTI). Flask-Reuploaded has been patched in version 1.5.0. Some workarounds are available. Do not pass user input to the `name` parameter, use auto-generated filenames only, and implement strict input validation if `name` must be used.","status":"published","published":"2026-02-25T03:54:54Z","modified":"2026-02-25T21:12:45Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T19:48:28.012266Z"}],"ghsa":[{"id":"GHSA-65mp-fq8v-56jr","title":"Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection","description":"### 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.","status":"published","published":"2026-02-25T19:06:50Z","modified":"2026-10-27T16:38:55Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-22","CWE-1336"],"updated_at":"2026-11-02T14:41:38.969831Z"}],"nvd":[{"id":"CVE-2026-27641","description":"Flask-Reuploaded provides file uploads for Flask. A critical path traversal and extension bypass vulnerability in versions prior to 1.5.0 allows remote attackers to achieve arbitrary file write and remote code execution through Server-Side Template Injection (SSTI). Flask-Reuploaded has been patched in version 1.5.0. Some workarounds are available. Do not pass user input to the `name` parameter, use auto-generated filenames only, and implement strict input validation if `name` must be used.","status":"published","published":"2026-02-25T04:16:04.62Z","modified":"2026-06-17T10:27:26.56Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-1336","CWE-22"],"updated_at":"2026-11-02T14:12:07.027269Z"}],"osv":[{"id":"CVE-2026-27641","title":"Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection","description":"Flask-Reuploaded provides file uploads for Flask. A critical path traversal and extension bypass vulnerability in versions prior to 1.5.0 allows remote attackers to achieve arbitrary file write and remote code execution through Server-Side Template Injection (SSTI). Flask-Reuploaded has been patched in version 1.5.0. Some workarounds are available. Do not pass user input to the `name` parameter, use auto-generated filenames only, and implement strict input validation if `name` must be used.","status":"published","published":"2026-02-25T03:54:54.391Z","modified":"2026-10-28T02:30:27.658818873Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-1336"],"updated_at":"2026-11-02T15:45:00.180685Z"},{"id":"GHSA-65mp-fq8v-56jr","title":"Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection","description":"### 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.","status":"published","published":"2026-02-25T19:06:50Z","modified":"2026-10-27T17:00:03.992051129Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-1336","CWE-22"],"updated_at":"2026-11-02T15:46:39.266402Z"},{"id":"PYSEC-2026-341","title":"Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection","description":"### 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\n Flask-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\n 3. 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()\n safe_name = secure_filename(request.form.get('custom_name'))\n# Remove path separators\n safe_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.","status":"published","published":"2026-06-29T11:50:51.002002Z","modified":"2026-07-01T20:22:53.047171Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:52:56.847083Z"}]}}