{"id":"CVE-2026-53909","aliases":["EUVD-2026-40955","GHSA-5v97-p7p8-r448"],"status":"published","title":"Arbitrary File Upload in MCO","description":"MCO does not correctly validate types of uploaded files. File upload validation functionality relies only on client-side checks, which can be bypassed. An authorized, low-privileged attacker can upload files with arbitrary types to the server.\n\nBecause vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.","severity":{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00394,"percentile":0.33908,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-434"],"published":"2026-07-01T11:59:26Z","modified":"2026-10-25T17:10:00Z","products":[{"vendor":"mycomplianceoffice","product":"mco"},{"vendor":"mycomplianceoffice","product":"mycomplianceoffice"}],"references":[{"url":"https://cert.pl/en/posts/2026/07/CVE-2026-53902","tags":["third-party-advisory","Third Party Advisory"]},{"url":"https://mco.mycomplianceoffice.com/","tags":["product","Product"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53909"},{"url":"https://mco.mycomplianceoffice.com"},{"url":"https://github.com/advisories/GHSA-5v97-p7p8-r448"}],"sources":{"cve":[{"id":"CVE-2026-53909","title":"Arbitrary File Upload in MCO","description":"MCO does not correctly validate types of uploaded files. File upload validation functionality relies only on client-side checks, which can be bypassed. An authorized, low-privileged attacker can upload files with arbitrary types to the server.\n\nBecause vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.","status":"published","published":"2026-07-01T11:59:26.104Z","modified":"2026-07-01T13:37:13.787Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T14:20:00.11477Z"}],"euvd":[{"id":"EUVD-2026-40955","description":"MCO does not correctly validate types of uploaded files. File upload validation functionality relies only on client-side checks, which can be bypassed. An authorized, low-privileged attacker can upload files with arbitrary types to the server.\n\nBecause vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.","status":"published","published":"2026-07-01T11:59:26Z","modified":"2026-07-01T13:37:13Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:20:20.297775Z"}],"ghsa":[{"id":"GHSA-5v97-p7p8-r448","title":"MCO does not correctly validate types of uploaded files. File upload validation functionality...","description":"MCO does not correctly validate types of uploaded files. File upload validation functionality relies only on client-side checks, which can be bypassed. An authorized, low-privileged attacker can upload files with arbitrary types to the server.\n\nBecause vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.","status":"published","published":"2026-07-01T15:35:18Z","modified":"2026-07-06T15:31:50Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/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","level":"medium"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T15:09:17.527527Z"}],"nvd":[{"id":"CVE-2026-53909","description":"MCO does not correctly validate types of uploaded files. File upload validation functionality relies only on client-side checks, which can be bypassed. An authorized, low-privileged attacker can upload files with arbitrary types to the server.\n\nBecause vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.","status":"published","published":"2026-07-01T13:17:46.08Z","modified":"2026-10-25T17:10:00.197Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/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","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T14:12:27.199837Z"}]}}