CVE-2023-40044: Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 8 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 90.4%
EPSS score, percentile 99.8 of all scored records
- How severe?
- 10.0 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline . Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Which versions are affected?
Affected
- from 8.8.0 to before 8.8.2
- from 8.7.0 to before 8.7.4
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CISA due date for this action: .
Advisories and patches
Linked from CISA's catalog entry
- https://community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023
- https://nvd.nist.gov/vuln/detail/CVE-2023-40044
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 8.8.0 to before 8.8.2 |
| Affected | from 8.7.0 to before 8.7.4 |
Versions not listed are: affected.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
Progress WS_FTP Server contains a deserialization of untrusted data vulnerability in the Ad Hoc Transfer module that allows an authenticated attacker to execute remote commands on the underlying operating system.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2023-40044 to its Known Exploited Vulnerabilities (KEV) catalog on 5 Oct 2023.
- CISA marks it as known to be used in ransomware campaigns.
- The due date CISA sets for the required action is 26 Oct 2023.
- The CVE record was published on 27 Sep 2023, 8 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 10.0 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 90.4% (percentile 99.8), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
WS_FTP Server Ad Hoc Transfer Module .NET Deserialization Vulnerability
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
- CWE-502: Deserialization of Untrusted Data
Attack patterns (CAPEC)
- CAPEC-586: Object Injection
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CISA due date for the required action | |
| CVE record last updated |
References
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