Vulnerability · Published Sep 24, 2026 · Assigned by VulnCheck
CVE-2026-97359HFS2 2.4.0 RCE via Multipart Upload Filename Template Injection
Critical 10.0
In plain English
A critical-severity security flaw in hfs2 from rejetto. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 5.5% (higher than 93% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei.
Official description
HFS2 version 2.4.0 and earlier contains a template injection vulnerability in the multipart upload handler that allows unauthenticated attackers to achieve remote code execution by embedding malicious template syntax in a filename. Attackers can craft a filename containing a closing template quoting sequence followed by an exec macro, which bypasses the authorization check in the dispatcher to execute arbitrary commands on the underlying host system.
Affected products (as reported)
Weakness: CWE-1336 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
References
- https://github.com/wgetnz/hfs2/blob/master/advisories/hfs2-upload-filename-template-injection/README.md technical-description, exploit
- VulnCheck Advisory third-party-advisory