{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53909","assignerOrgId":"4bb8329e-dd38-46c1-aafb-9bf32bcb93c6","state":"PUBLISHED","assignerShortName":"CERT-PL","dateReserved":"2026-06-11T07:44:52.179Z","datePublished":"2026-07-01T11:59:26.104Z","dateUpdated":"2026-07-01T13:37:13.787Z"},"containers":{"cna":{"providerMetadata":{"orgId":"4bb8329e-dd38-46c1-aafb-9bf32bcb93c6","shortName":"CERT-PL","dateUpdated":"2026-07-01T11:59:26.104Z"},"title":"Arbitrary File Upload in MCO","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-434","description":"CWE-434 Unrestricted Upload of File with Dangerous Type","type":"CWE"}]}],"affected":[{"vendor":"MyComplianceOffice","product":"MCO","versions":[{"status":"affected","version":"25.3.3.1","versionType":"custom"}],"defaultStatus":"unknown"}],"descriptions":[{"lang":"en","value":"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.","supportingMedia":[{"type":"text/html","base64":false,"value":"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.<br><br>Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1&nbsp;but may also affect other versions."}]}],"references":[{"url":"https://cert.pl/en/posts/2026/07/CVE-2026-53902","tags":["third-party-advisory"]},{"url":"https://mco.mycomplianceoffice.com/","tags":["product"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","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":"MEDIUM","baseScore":5.3,"vectorString":"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"}}],"credits":[{"lang":"en","value":"Hubert Decyusz (AFINE Team)","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-01T13:37:06.566970Z","id":"CVE-2026-53909","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-01T13:37:13.787Z"}}]}}