Critical severity · published Feb 25, 2026
CVE-2026-27641
Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection
9.8
CVSS
1.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.3% · higher than 71% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FL
flask-reuploaded · jugmac00
< 1.5.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27641
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-27641
Patch
https://github.com/jugmac00/flask-reuploaded/commit/d64c6b2f71cb73734fc38baa0e3e156926361288
Issue Tracking
https://github.com/jugmac00/flask-reuploaded/pull/180
Exploit
https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-65mp-fq8v-56jr
More from flask-reuploaded
7.5
CVE-2026-54567
Flask-Reuploaded: Extension-denylist bypass via case-folding asymmetry in name-override path (incomplete-fix variant of CVE-2026-27641)