{"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"],"vendor":"cisagov","product":"Malcolm","affected":["Malcolm < 26.06.1"],"published":"2026-08-11","updated":"2026-10-02","sourceUpdated":"2026-10-02T21:16:55.597","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55676","references":[{"url":"https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-230-01.json","label":"ics-cert@hq.dhs.gov"},{"url":"https://github.com/cisagov/Malcolm/releases/tag/v26.06.1","label":"ics-cert@hq.dhs.gov"},{"url":"https://github.com/cisagov/Malcolm/security/advisories/GHSA-8cvp-m7pg-qrp7","label":"ics-cert@hq.dhs.gov"},{"url":"https://www.cisa.gov/news-events/ics-advisories/icsa-26-230-01","label":"ics-cert@hq.dhs.gov"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-08-12T22:09:13.650474Z"},"epss":0.00601,"epssPercentile":0.48541,"ingestedAt":"2026-09-09T21:22:45.530Z","slug":"CVE-2026-55676","body":"## Overview\n\nMalcolm 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}