{"id":"CVE-2026-53903","state":"PUBLISHED","title":"Insecure Direct Object Reference in MCO","description":"MCO is vulnerable to an Insecure Direct Object Reference (IDOR) vulnerability in the /customer/servlet/mco/webapi/trading-document/fetchPdfStatement endpoint. The application does not properly validate whether an authenticated user is authorized to access a requested document, allowing direct retrieval based on a user-supplied identifier.\nAn attacker can access trading documents belonging to other users by providing a valid document ID. Although exploitation requires guessing the identifier, predictable ID patterns enable feasible enumeration, leading to unauthorized disclosure of sensitive information.\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.","publishedAt":"2026-07-01T11:58:36.922Z","updatedAt":"2026-07-01T13:42:31.836Z","severity":{"score":5.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","source":"CERT-PL"},"assigner":"CERT-PL","products":["MyComplianceOffice MCO"],"affected":[{"vendor":"MyComplianceOffice","product":"MCO","defaultStatus":"unknown","versions":[{"version":"25.3.3.1","status":"affected","versionType":"custom"}]}],"references":["https://cert.pl/en/posts/2026/07/CVE-2026-53902","https://mco.mycomplianceoffice.com/"],"weaknesses":["CWE-639"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53903.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53903","state":"PUBLISHED","datePublished":"2026-07-01T11:58:36.922Z","dateUpdated":"2026-07-01T13:42:31.836Z","assignerShortName":"CERT-PL","assignerOrgId":"4bb8329e-dd38-46c1-aafb-9bf32bcb93c6","dateReserved":"2026-06-11T07:44:52.179Z"},"containers":{"cna":{"title":"Insecure Direct Object Reference in MCO","descriptions":[{"lang":"en","value":"MCO is vulnerable to an Insecure Direct Object Reference (IDOR) vulnerability in the /customer/servlet/mco/webapi/trading-document/fetchPdfStatement endpoint. The application does not properly validate whether an authenticated user is authorized to access a requested document, allowing direct retrieval based on a user-supplied identifier.\nAn attacker can access trading documents belonging to other users by providing a valid document ID. Although exploitation requires guessing the identifier, predictable ID patterns enable feasible enumeration, leading to unauthorized disclosure of sensitive information.\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."}],"affected":[{"vendor":"MyComplianceOffice","product":"MCO","defaultStatus":"unknown","versions":[{"version":"25.3.3.1","status":"affected","versionType":"custom"}]}],"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":"LOW","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","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:L/VI:N/VA:N/SC:N/SI:N/SA:N"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-639","lang":"en","description":"CWE-639 Authorization Bypass Through User-Controlled Key","type":"CWE"}]}],"providerMetadata":{"shortName":"CERT-PL","orgId":"4bb8329e-dd38-46c1-aafb-9bf32bcb93c6","dateUpdated":"2026-07-01T11:58:36.922Z"},"credits":[{"lang":"en","value":"Hubert Decyusz (AFINE Team)","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-01T13:42:26.696418Z","id":"CVE-2026-53903","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-01T13:42:31.836Z"}}]}}}