GHSA-65mp-fq8v-56jr
Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| PyPI | flask-reuploaded | < 1.5.0 | 1.5.0 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
A 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).
### Patches
Flask-Reuploaded has been patched in version 1.5.0
### Workarounds
1. **Do not pass user input to the `name` parameter**
2. Use auto-generated filenames only
3. Implement strict input validation if `name` must be used
```python
from werkzeug.utils import secure_filename
import os
# Sanitize user input before passing to save()
safe_name = secure_filename(request.form.get('custom_name'))
# Remove path separators
safe_name = os.path.basename(safe_name)
# Validate extension matches policy
if not photos.extension_allowed(photos.get_extension(safe_name)):
abort(400)
filename = photos.save(file, name=safe_name)
```
### Resources
The fix is documented in the pull request, see https://github.com/jugmac00/flask-reuploaded/pull/180.
A 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.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-65mp-fq8v-56jr
- https://nvd.nist.gov/vuln/detail/CVE-2026-27641
- https://github.com/jugmac00/flask-reuploaded/pull/180
- https://github.com/jugmac00/flask-reuploaded/commit/d64c6b2f71cb73734fc38baa0e3e156926361288
- https://github.com/jugmac00/flask-reuploaded
- https://github.com/pypa/advisory-database/tree/main/vulns/flask-reuploaded/PYSEC-2026-341.yaml
- https://pypi.org/project/flask-reuploaded