{ "dataType": "CVE_RECORD", "cveMetadata": { "cveId": "CVE-2026-55676", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-17T00:05:03.778Z", "datePublished": "2026-08-11T20:24:50.803Z", "dateUpdated": "2026-10-02T20:20:14.228Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "7d14cffa-0d7d-4270-9dc0-52cabd5a23a6", "shortName": "icscert", "dateUpdated": "2026-10-02T20:20:14.228Z" }, "title": "Malcolm vulnerable to RCE via unrestricted .php upload to the file-upload component", "problemTypes": [ { "descriptions": [ { "lang": "en", "cweId": "CWE-434", "description": "CWE-434: Unrestricted Upload of File with Dangerous Type", "type": "CWE" } ] } ], "affected": [ { "vendor": "cisagov", "product": "Malcolm", "versions": [ { "status": "affected", "version": "< 26.06.1" }, { "status": "unaffected", "version": "26.06.1" } ], "defaultStatus": "unaffected" } ], "descriptions": [ { "lang": "en", "value": "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.", "supportingMedia": [ { "type": "text/html", "base64": false, "value": "

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.

" } ] } ], "references": [ { "url": "https://github.com/cisagov/Malcolm/security/advisories/GHSA-8cvp-m7pg-qrp7", "name": "https://github.com/cisagov/Malcolm/security/advisories/GHSA-8cvp-m7pg-qrp7", "tags": [ "x_refsource_CONFIRM" ] }, { "url": "https://github.com/cisagov/Malcolm/releases/tag/v26.06.1", "name": "https://github.com/cisagov/Malcolm/releases/tag/v26.06.1", "tags": [ "x_refsource_MISC" ] }, { "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-230-01" }, { "url": "https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-230-01.json" } ], "metrics": [ { "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ], "cvssV3_1": { "version": "3.1", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 8.8, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } }, { "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ], "cvssV4_0": { "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "HIGH", "baseScore": 8.7, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N" } } ], "solutions": [ { "lang": "en", "value": "Malcolm version 26.06.1 addresses this issue. For more information, see  https://github.com/cisagov/Malcolm/pull/1026", "supportingMedia": [ { "type": "text/html", "base64": false, "value": "Malcolm version 26.06.1 addresses this issue. For more information, see https://github.com/cisagov/Malcolm/pull/1026" } ] } ], "credits": [ { "lang": "en", "value": "kah-ja, DeathRipper21 reported CVE-2026-55676 to CISA.", "type": "finder" } ], "source": { "advisory": "GHSA-8cvp-m7pg-qrp7", "discovery": "EXTERNAL" }, "x_generator": { "engine": "Vulnogram 1.0.5" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-08-12T22:09:13.650474Z", "id": "CVE-2026-55676", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-12T22:13:05.815Z" } } ] }, "dataVersion": "5.2" }