CVE-2024-55956: Cleo Multiple Products Unauthenticated File Upload Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 17 Dec 2024, 4 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 94%
EPSS score, percentile 99.8 of all scored records
- How severe?
- 9.8 Critical
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline 7 Jan 2025. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. 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: 7 January 2025.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Update-CVE-2024-55956
- https://nvd.nist.gov/vuln/detail/CVE-2024-55956
Affected products and versions
The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
Cleo Harmony, VLTrader, and LexiCom, which are managed file transfer products, contain an unrestricted file upload vulnerability that could allow an unauthenticated user to import and execute arbitrary bash or PowerShell commands on the host system by leveraging the default settings of the Autorun directory.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2024-55956 to its Known Exploited Vulnerabilities (KEV) catalog on 17 Dec 2024.
- CISA marks it as known to be used in ransomware campaigns.
- The due date CISA sets for the required action is 7 Jan 2025.
- The CVE record was published on 13 Dec 2024, 4 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 9.8 (Critical), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 94% (percentile 99.8), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
In Cleo Harmony before 5.8.0.24, VLTrader before 5.8.0.24, and LexiCom before 5.8.0.24, an unauthenticated user can import and execute arbitrary Bash or PowerShell commands on the host system by leveraging the default settings of the Autorun directory.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 13 Dec 2024 | CVE record published |
| 17 Dec 2024 | Added to CISA KEV |
| 7 Jan 2025 | CISA due date for the required action |
| 5 Aug 2026 | CVE record last updated |
References
More exploited Cleo vulnerabilities
- CVE-2024-50623: Cleo Multiple Products Unrestricted File Upload Vulnerability