CVE-2026-27641: Flask-Reuploaded vulnerable to Remote Code Execution via Server-Side Template Injection
Affects flask-reuploadedSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical : upgrade to 1.5.0 as a priority.
Data as of 27 Oct 2026, 17:29 UTC
- Patch
- Available – fixed in 1.5.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade flask-reuploaded to 1.5.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| PyPIflask-reuploaded | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and included in Flask-Reuploaded version 1.5.0; upgrading to this version fully mitigates the vulnerability. Until upgrading, do not pass user input directly to the 'name' parameter when saving files. Use auto-generated filenames or sanitize and validate any user-supplied filenames using secure_filename and strict extension checks as demonstrated in the vendor's recommended workaround.
Description
Flask-Reuploaded versions prior to 1.5.0 contain a critical vulnerability allowing remote code execution via Server-Side Template Injection (SSTI). This flaw involves path traversal and extension bypass, enabling attackers to write arbitrary files. The issue is fixed in version 1.5.0. Mitigations include avoiding user input in the 'name' parameter, using auto-generated filenames, or applying strict input validation and sanitization.
References
- github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-65mp-fq8v-56jr (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-27641 (opens in a new tab)
- github.com/jugmac00/flask-reuploaded/pull/180 (opens in a new tab)
- github.com/jugmac00/flask-reuploaded/commit/d64c6b2f71cb73734fc38baa0e3e156926361288 (opens in a new tab)
- github.com/jugmac00/flask-reuploaded (opens in a new tab)
- github.com/pypa/advisory-database/tree/main/vulns/flask-reuploaded/PYSEC-2026-341.yaml (opens in a new tab)
- pypi.org/project/flask-reuploaded (opens in a new tab)