---
cve: "CVE-2026-55676"
severity: "HIGH"
cvss: 8.8
epss: "30%"
vendor: "cisagov"
kev: false
exploited: false
published: "2026-08-11 21:17:37"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-13T07:32:48+02:00"
---

# CVE-2026-55676

> 8.8 HIGH · 🧪 PoC

## Beschreibung

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/.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.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- 6a4e6b16b72803562465a7ba3e9135fee733fb89 (Commit)

## Referenzen

- <https://github.com/cisagov/Malcolm/security/advisories/GHSA-8cvp-m7pg-qrp7>
- <https://github.com/cisagov/Malcolm/releases/tag/v26.06.1>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-55676) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_