Description
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.
Published: 2026-09-24
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service
Action: Immediate Patch
AI Analysis

Impact

A crafted request to HFS2 version 2.4.0 or earlier forces the server to enter a perpetually busy loop, consuming CPU and preventing any new connections from being served. The resulting state persists until the service is manually restarted, effectively causing a permanent outage for all users.

Affected Systems

Rejetto HFS2 file server, version 2.4.0 and all earlier releases. The vulnerability affects any deployment of this software regardless of platform.

Risk and Exploitability

The CVSS score of 8.7 classifies the issue as high severity. No EPSS score is available, and the vulnerability is not listed in the CISA KEV catalog. Only an unauthenticated request is required, so the attack can be launched from any network location that can reach the server. Persistent denial of service with no automatic recovery makes the impact critical for environments where the file server is a single point of failure.

Generated by OpenCVE AI on September 25, 2026 at 11:31 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade Rejetto HFS2 to a patched version newer than 2.4.0.
  • If an immediate upgrade is not possible, limit network exposure by placing the server behind a firewall that permits only trusted IP addresses.
  • In the event a hung thread occurs, manually restart the service and monitor for recurring behavior.

Generated by OpenCVE AI on September 25, 2026 at 11:31 UTC.

Tracking

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Advisories

No advisories yet.

History

Thu, 24 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 24 Sep 2026 15:00:00 +0000

Type Values Removed Values Added
Description 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.
Title HFS2 2.4.0 Unauthenticated Denial of Service via Hung Serving Thread
First Time appeared Rejetto
Rejetto hfs2
Weaknesses CWE-835
CPEs cpe:2.3:a:rejetto:hfs2:*:*:*:*:*:*:*:*
Vendors & Products Rejetto
Rejetto hfs2
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

Rejetto Hfs2
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-24T15:47:35.811Z

Reserved: 2026-09-24T13:33:30.061Z

Link: CVE-2026-97362

cve-icon Vulnrichment

Updated: 2026-09-24T15:46:09.398Z

cve-icon NVD

Status : Deferred

Published: 2026-09-24T15:18:01.393

Modified: 2026-09-24T21:08:55.030

Link: CVE-2026-97362

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-25T11:45:19Z

Weaknesses
  • CWE-835

    Loop with Unreachable Exit Condition ('Infinite Loop')