CVE-2026-55676
Malcolm vulnerable to RCE via unrestricted .php upload to the file-upload component
Description
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.
INFO
Published Date :
Aug. 11, 2026, 9:17 p.m.
Last Modified :
Oct. 24, 2026, 4:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-55676
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Malcolm to version 26.06.1.
- Ensure file upload restrictions are properly configured.
- Review RBAC roles for file upload permissions.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-55676.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-55676 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-55676
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-55676 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-55676 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 24, 2026
Action Type Old Value New Value Changed Translation Title: Malcolm de cisagov, Description: Malcolm es un conjunto de herramientas de análisis de tráfico de red. El componente de carga de archivos (backend PHP de FilePond) acepta cargas en POST /server/php/submit.php y las almacena en un directorio servido por la misma instancia de nginx y php-fpm. La lista de permitidos que debería restringir los tipos de archivo aceptados es un array vacío por defecto (file-upload/php/config.php:16), por lo que la verificación de tipo es una operación nula y cada extensión es aceptada. El saneador de nombres de archivo mantiene la extensión .php intacta. Los archivos confirmados aterrizan en /var/www/upload/server/php/files (file-upload/php/config.php:7), y el nginx del componente enruta cualquier URL que termine en .php a php-fpm. Un GET /server/php/files/[name].php autenticado luego ejecuta el código cargado como www-data. Antes de la versión 26.06.1, en modo RBAC, el endpoint de carga es accesible por el rol granular ROLE_UPLOAD (nginx/lua/nginx_auth_helpers.lua:71), un rol destinado solo para enviar archivos de captura. Como resultado, un usuario con el rol de solo carga ejecuta PHP arbitrario como www-data dentro del contenedor de carga de archivos. La versión 26.06.1 corrige el problema. Title: Malcolm de cisagov, Description: Malcolm es un conjunto de herramientas de análisis de tráfico de red. El componente de carga de archivos (backend PHP de FilePond) acepta cargas en POST /server/php/submit.php y las almacena en un directorio servido por la misma instancia de nginx y php-fpm. La lista de permitidos que debería restringir los tipos de archivo aceptados es un array vacío por defecto (file-upload/php/config.php:16), por lo que la verificación de tipo es una operación nula y cada extensión es aceptada. El saneador de nombres de archivo mantiene la extensión .php intacta. Los archivos confirmados aterrizan en /var/www/upload/server/php/files (file-upload/php/config.php:7), y el nginx del componente enruta cualquier URL que termine en .php a php-fpm. Un GET /server/php/files/[name].php autenticado luego ejecuta el código cargado como www-data. Antes de la versión 26.06.1, en modo RBAC, el endpoint de carga es accesible por el rol granular ROLE_UPLOAD (nginx/lua/nginx_auth_helpers.lua:71), un rol destinado solo para enviar archivos de captura. Como resultado, un usuario con el rol de solo carga ejecuta PHP arbitrario como www-data dentro del contenedor de carga de archivos. La versión 26.06.1 corrige el problema. -
CVE Translated by [email protected]
Oct. 23, 2026
Action Type Old Value New Value Added Translation Title: Malcolm de cisagov, Description: Malcolm es un conjunto de herramientas de análisis de tráfico de red. El componente de carga de archivos (backend PHP de FilePond) acepta cargas en POST /server/php/submit.php y las almacena en un directorio servido por la misma instancia de nginx y php-fpm. La lista de permitidos que debería restringir los tipos de archivo aceptados es un array vacío por defecto (file-upload/php/config.php:16), por lo que la verificación de tipo es una operación nula y cada extensión es aceptada. El saneador de nombres de archivo mantiene la extensión .php intacta. Los archivos confirmados aterrizan en /var/www/upload/server/php/files (file-upload/php/config.php:7), y el nginx del componente enruta cualquier URL que termine en .php a php-fpm. Un GET /server/php/files/[name].php autenticado luego ejecuta el código cargado como www-data. Antes de la versión 26.06.1, en modo RBAC, el endpoint de carga es accesible por el rol granular ROLE_UPLOAD (nginx/lua/nginx_auth_helpers.lua:71), un rol destinado solo para enviar archivos de captura. Como resultado, un usuario con el rol de solo carga ejecuta PHP arbitrario como www-data dentro del contenedor de carga de archivos. La versión 26.06.1 corrige el problema. -
CVE Modified by [email protected]
Oct. 02, 2026
Action Type Old Value New Value Changed Description 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. 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-434 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/55xxx/CVE-2026-55676.json">CVE-2026-55676</a> Added Reference https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-230-01.json Added Reference https://github.com/cisagov/Malcolm/releases/tag/v26.06.1 Added Reference https://github.com/cisagov/Malcolm/security/advisories/GHSA-8cvp-m7pg-qrp7 Added Reference https://www.cisa.gov/news-events/ics-advisories/icsa-26-230-01 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 12, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-55676', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-12T22:09:13.650474Z'} -
New CVE Received by [email protected]
Aug. 11, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'cisagov', 'product': 'Malcolm', 'versions': [{'status': 'affected', 'version': '< 26.06.1'}]}] Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-434 Added Reference https://github.com/cisagov/Malcolm/releases/tag/v26.06.1 Added Reference https://github.com/cisagov/Malcolm/security/advisories/GHSA-8cvp-m7pg-qrp7