CVE-2026-27641

CRITICAL

Flask-Reuploaded <1.5.0 - Path Traversal

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-27641. PoCs published by Max78000.

AI-analyzed exploit summary This PoC demonstrates an arbitrary file write vulnerability in Flask-Reuploaded < 1.5.0 by exploiting improper path sanitization in file uploads. Attackers can traverse directories using crafted filenames (e.g., `../../malicious.txt`) to write files outside the intended upload directory.

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.

Exploits (1)

github WORKING POC
by Max78000 · pythonpoc
https://github.com/Max78000/CVE-2026-27641-Flask-Reuploaded

This PoC demonstrates an arbitrary file write vulnerability in Flask-Reuploaded < 1.5.0 by exploiting improper path sanitization in file uploads. Attackers can traverse directories using crafted filenames (e.g., `../../malicious.txt`) to write files outside the intended upload directory.

Classification
Working Poc 98%
Attack Type
Other
Complexity
Trivial
Reliability
Reliable
Target: Flask-Reuploaded versions < 1.5.0
No auth needed
Prerequisites: Target must have a Flask application using Flask-Reuploaded with file uploads enabled · Attacker must know the upload endpoint URL
mistral-large-3 · analyzed Jul 23, 2026 Full analysis →

Scores

CVSS v3 9.8
EPSS 0.0105
EPSS Percentile 60.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-1336 CWE-22
Status published
Products (2)
jugmac00/flask-reuploaded < 1.5.0
pypi/flask-reuploaded 0 - 1.5.0PyPI
Published Feb 25, 2026
Tracked Since Feb 25, 2026