CVE-2024-55956
CriticalExploitedPublic exploitIn 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.
Published Dec 13, 2024 · Updated Aug 5, 2026
Key Facts
Patch immediately- CVE-2024-55956 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Harmony (Cleo), Lexicom (Cleo), Vltrader (Cleo).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Dec 10, 2024 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 94% probability of exploitation in the next 30 days.
- Fixed versions are available, including Harmony 5.8.0.24, Lexicom 5.8.0.24, Vltrader 5.8.0.24.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
94%
Higher than 99.8% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2024-55956 brief as a PDF
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Dec 17, 2024 | Jan 7, 2025 | Known |
| Industry KEV feed | Dec 10, 2024 | Jan 7, 2025 | Known |
| CIRCL KEV | Dec 17, 2024 | Jan 7, 2025 | Known |
| ENISA EUVD | Dec 17, 2024 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HarmonyCleo | See advisory | 5.8.0.24 |
| LexicomCleo | See advisory | 5.8.0.24 |
| VltraderCleo | See advisory | 5.8.0.24 |
Patched Releases
Harmony
5.8.0.24
Lexicom
5.8.0.24
Vltrader
5.8.0.24
Timeline
Added to Industry KEV feed
Dec 10, 2024
Publicly disclosed
Dec 13, 2024
Added to CISA KEV
Dec 17, 2024
Added to CIRCL KEV
Dec 17, 2024
Added to ENISA EUVD
Dec 17, 2024
Last updated
Aug 5, 2026
Weakness Type
- CWE-77 Improper Neutralization of Special Elements used in a Command ('Command Injection')
References
- advisoryhttps://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Advisory-CVE-Pending
- advisoryhttps://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Update
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
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.
Affected: Harmony (Cleo); Lexicom (Cleo); Vltrader (Cleo). The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Dec 10, 2024 and is known to be used in ransomware campaigns.
Yes. It was added on Dec 17, 2024 with a federal remediation due date of Jan 7, 2025.
Public exploit code is available.
Fixed versions are available, including Harmony 5.8.0.24, Lexicom 5.8.0.24, Vltrader 5.8.0.24.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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