---
id: CVE-2026-55676
title: Malcolm is a network traffic analysis tool suite
summary: >-
  Malcolm is a network traffic analysis tool suite. The file-upload component
  (FilePond PHP backend) accepts uploads at `POST /server/php/submit.php` and
  stores them in a directory served by the same nginx and php-fpm instance. The
  allow-l…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-434
published: '2026-08-11'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T20:46:28.353'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55676'
references:
  - url: 'https://github.com/cisagov/Malcolm/releases/tag/v26.06.1'
    label: security-advisories@github.com
  - url: 'https://github.com/cisagov/Malcolm/security/advisories/GHSA-8cvp-m7pg-qrp7'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00508
epssPercentile: 0.40797
ingestedAt: '2026-09-09T21:22:45.530Z'
---

## Overview

Malcolm is a network traffic analysis tool suite. The file-upload component (FilePond PHP backend) accepts uploads at `POST /server/php/submit.php` and stores them in a directory served by the same nginx and php-fpm instance. The allow-list that should restrict accepted file types is an empty array by default (`file-upload/php/config.php:16`), so the type check is a no-op and every extension is accepted. The filename sanitizer keeps the `.php` extension intact. Committed files land in `/var/www/upload/server/php/files` (`file-upload/php/config.php:7`), and the component's nginx routes any URL ending in `.php` to php-fpm. An authenticated `GET /server/php/files/<name>.php` then executes the uploaded code as `www-data`. Prior to version 26.06.1, in RBAC mode, the upload endpoint is reachable by the granular `ROLE_UPLOAD` role (`nginx/lua/nginx_auth_helpers.lua:71`), a role intended only for submitting capture files. As a result, a user holding the upload-only role runs arbitrary PHP as `www-data` inside the file-upload container. Version 26.06.1 fixes the issue.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.