Vulnerability 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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/cisagov/Malcolm/releases/tag/v26.06.1
- https://github.com/cisagov/Malcolm/security/advisories/GHSA-8cvp-m7pg-qrp7
FAQ
What is CVE-2026-55676?
CVE-2026-55676 is a vulnerability with a CVSS score of 8.8 (HIGH). 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 ng...
How severe is CVE-2026-55676?
CVE-2026-55676 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-55676?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.