TI-2026-64044 Aliases CVE-2026-97362 GHSA-99rf-x5r6-q76q

HFS2 2.4.0 Unauthenticated Denial of Service via Hung Serving Thread

HIGH 77CWE-835Published 2026-09-24 · Updated 2026-09-24

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-835.

Summary

HFS2 version 2.4.0 and earlier contains a denial of service vulnerability that allows unauthenticated attackers to cause a complete and persistent loss of availability by sending a single crafted request. Attackers can trigger a hung serving thread that enters a busy loop, rendering the entire file server unresponsive to all clients without self-recovery until an operator manually restarts the service.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00291 21st percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by the CNA

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Rejetto	hfs2	2.0.0 – 2.4.0	—	No fix listed	CNA

hfs2 VendorRejetto Affected 2.0.0 – 2.4.0 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2026-97362
2026-10-03 Alias added: GHSA-99rf-x5r6-q76q

References

Exploit 1

https://github.com/wgetnz/hfs2/blob/master/advisories/hfs2-getini-infinite-loop-dos/README.md

TI-2024-15709 Rejetto HTTP File Server 2.3m Unauthenticated RCE KEVCVSS 3.1CRITICAL 9.8
TI-2014-05168 The findMacroMarker function in parserLib.pas in Rejetto HTTP File Server (aks HFS or… KEVCVSS 3.1CRITICAL 9.8
TI-2026-64043 HFS2 2.4.0 Unauthenticated Arbitrary File Read/Write via Template Engine CVSS 4.0CRITICAL 10.0
TI-2026-64042 HFS2 2.4.0 RCE via Multipart Upload Filename Template Injection CVSS 4.0CRITICAL 10.0
TI-2024-26831 rejetto HFS (aka HTTP File Server) 3 before 0.52.10 on Linux, UNIX, and macOS allows OS… CVSS 3.1CRITICAL 9.9
TI-2020-10536 rejetto HFS (aka HTTP File Server) v2.3m Build #300, when virtual files or folders are… CVSS 3.1HIGH 7.5

See all 15 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences