File Upload Vulnerability in Malcolm Network Traffic Analysis Tool
CVE-2026-55676

8.8HIGH

Key Information:

Vendor

Cisagov

Status
Malcolm
Vendor
CVE Published:
11 August 2026

What is CVE-2026-55676?

The Malcolm network traffic analysis tool contains a vulnerability in its file-upload component, which allows unrestricted file uploads due to an empty allow-list for accepted file types. This flaw permits attackers to upload malicious files, retaining their PHP extensions. The uploaded files are subsequently executable by users in the upload role, potentially leading to arbitrary code execution within the server environment. Affected versions before 26.06.1 are particularly at risk, as the vulnerability enables execution of unauthorized PHP code as the 'www-data' user. An update to version 26.06.1 addresses this issue, closing the exploit.

Affected Version(s)

Malcolm < 26.06.1

References

https://github.com/cisagov/Malcolm/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/cisagov/Malcolm/releases/tag/v26.06.1
x_refsource_MISC

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.