CVE-2026-27641CWE-1336

Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection

Critical · published February 25, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
69.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.01266 · 69.5th percentile
Weakness
CWE-1336 · Improper Neutralization of Special Elements Used in a Template Engine
Published
2026-02-25T03:54Z
EPSS history
Timeline
  • 25 FEB 03:54Z
    Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection
    cvelistv5