Critical 10.0Known exploited (CISA KEV)Published Sep 27, 2023

CVE-2023-40044WS_FTP Server Ad Hoc Transfer Module .NET Deserialization Vulnerability

Updated under an hour ago (2026-10-19 11:20 UTC)

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It affects Progress Software Corporation WS_FTP Server and 1 other product. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Oct 5, 2023; federal agencies had to remediate by Oct 26, 2023, and it is known to be used in ransomware. Treat that date as your deadline.

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Every CVE for Progress Software Corporation WS_FTP Server

Exploited in the last 30 days

In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a pre-authenticated attacker could leverage a .NET deserialization vulnerability in the Ad Hoc Transfer module to execute remote commands on the underlying WS_FTP Server operating system.

CVSS: 10.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-502
Known exploited: Added to CISA KEV Oct 5, 2023; federal remediation due Oct 26, 2023; known ransomware useApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
EPSS (exploitation in the next 30 days): 90.35% (percentile 100)
Assigned by: ProgressSoftware
NVD analysis: Analyzed
Record last updated: Oct 21, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Progress Software Corporation WS_FTP Server progress_software:ws_ftp_server (from the name)	from 8.8.0 before 8.8.2; from 8.7.0 before 8.7.4	CNA record
progress ws_ftp_server progress:ws_ftp_server	before 8.7.4; from 8.8 before 8.8.2	NVD

References

https://www.progress.com/ws_ftpproduct
https://community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023vendor-advisory
https://www.theregister.com/2023/10/02/ws_ftp_update/press/media-coverage, third-party-advisory
https://www.rapid7.com/blog/post/2023/09/29/etr-critical-vulnerabilities-in-ws_ftp-server/broken-link, third-party-advisory
https://attackerkb.com/topics/bn32f9sNax/cve-2023-40044third-party-advisory
https://censys.com/cve-2023-40044/third-party-advisory
https://www.assetnote.io/resources/research/rce-in-progress-ws-ftp-ad-hoc-via-iis-http-modules-cve-2023-40044exploit, third-party-advisory
http://packetstormsecurity.com/files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.htmlexploit, third-party-advisory, vdb-entry
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-40044us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.