PatchTheCVECVE-2024-55956: Cleo Multiple Products Unauthenticated File Upload Vulnerability
CVE-2024-55956 is a critical-severity flaw (CVSS 9.8) affecting harmony, lexicom, vltrader, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Critical severity
- EPSS top 1%: very likely to be exploited
- Exploited in the wild (CISA KEV)
- Used in ransomware campaigns
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 94.0% (top 1%) |
| CISA exploited list | Yes, fix due 2025-01-07, used in ransomware |
| Weakness | CWE-77 |
| Published | 2024-12-13 |
| Last modified | 2026-08-05 |
Last updated 2026-08-05 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Exploited Added to the CISA Known Exploited Vulnerabilities list
- Deadline CISA due date for US federal agencies to patch
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- Write-up: support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Advisory-CVE-Pendi
- Write-up: support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Update
- Write-up: www.huntress.com/blog/threat-advisory-oh-no-cleo-cleo-software-actively-being-exploited-in
- Metasploit: Cleo LexiCom, VLTrader, and Harmony Unauthenticated Remote Code Execution
- Nuclei scan template: Cleo Harmony < 5.8.0.24 - File Upload Vulnerability
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2024-55956?
harmony: upgrade to 5.8.0.24; lexicom: upgrade to 5.8.0.24; vltrader: upgrade to 5.8.0.24. Exact commands for each OS are on this page.
Is CVE-2024-55956 being exploited?
Yes. CVE-2024-55956 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.
What does CVE-2024-55956 affect?
CVE-2024-55956 affects harmony, lexicom, vltrader. Severity is critical (CVSS 9.8). 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 Autoru
How urgent is CVE-2024-55956?
Priority 99/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; Remotely exploitable, no login, no user action
Software pages
PowerShell vulnerabilities · Cleo vulnerabilities
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