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Weekly Signal
Live intelligence Updated 19 Aug 2026 · 13:41 UTC

Progress · WS_FTP Server

CVE-2023-40044

Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability

Recommended action

Treat this as an immediate remediation priority. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

View response plan
CVSS8.8
EPSS90.1%
KEVYes
ExploitationConfirmed exploitation
PatchPatch or guidance available ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 90.1%; technical severity is CVSS 8.8.

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.

Who should care

  • Teams operating WS_FTP Server
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether WS_FTP Server is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Vendor remediation

Patch and remediation links

Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-502
Affected versions
Progress WS_FTP Server (Start Including: 8.8, End Excluding: 8.8.2)
Published
27 September 2023
Attack vector
Network
Privileges required
Low
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 90.1%
  4. Signal calculated at 86

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.