{"id":"CVE-2026-0856","revision":null,"records":[{"revision":"e80a853b87f0402fa9ee5ec63ff724f6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-0856","aliases":[],"title":"Improper Access Control vulnerability in Mesalvo MEONA (MEONA Client and MEONA Server) allows an authenticated MEONA user to access administrative functions of the MEONA Client (admin panel). The MEONA Server does not independently verify t…","description":"Improper Access Control vulnerability in Mesalvo MEONA (MEONA Client and MEONA Server) allows an authenticated MEONA user to access administrative functions of the MEONA Client (admin panel). The MEONA Server does not independently verify the role asserted by the MEONA Client. A user who holds a valid MEONA user account and is able to execute a modified copy of the MEONA Client on a device within the operating hospital's network can assert an administrator role and access administrative functions with regular user credentials.\nExploitation requires: (1) a valid MEONA user account issued by the operating hospital; (2) network access to the MEONA Server, which is operated exclusively within closed hospital networks without exposure to the public Internet (where a hospital permits remote access to that network at all, it is only through the hospital's own remote-access infrastructure (e.g. VPN) under the hospital's control); (3) the ability to modify MEONA Client binaries and to execute the modified copy on a device in that network. On managed devices with application control, as recommended in Mesalvo's hardening guidance (MSA-2026-001), this requires local administrator privileges on the device. Mesalvo is not aware of any exploitation outside the reported security test.\nThis issue affects MEONA Client and MEONA Server in versions 2024.10, 2025.04 and 2026.03. Mitigations are available with MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026); see Mesalvo Security Advisory MSA-2026-001.","state":0,"publishedAt":"2026-05-20T10:38:53.881+00:00","modifiedAt":"2026-09-25T15:44:21.119+00:00","affected":[{"ecosystem":"Vendor product","name":"Meona Client","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Mesalvo\",\n                    \"product\": \"Meona Client\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"2024.10\",\n                            \"versionType\": \"custom\"\n                        },\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"2025.04\",\n                            \"versionType\": \"custom\"\n                        },\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"2026.03\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"},{"ecosystem":"Vendor product","name":"Meona Server","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Mesalvo\",\n                    \"product\": \"Meona Server\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"2024.10\",\n                            \"versionType\": \"custom\"\n                        },\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"2025.04\",\n                            \"versionType\": \"custom\"\n                        },\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"2026.03\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://mesalvo.com/en/vdp/advisories/msa-2026-001.pdf"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-0856","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-0856","identifiers":["CVE-2026-0856"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-12T10:55:30.8237330+00:00","complete":true,"records":1779,"lastAttemptAt":"2026-11-12T10:55:30.823733+00:00","lastSuccessAt":"2026-11-12T10:55:31.0556782+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:55:31.055679+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-64752486c567b55b31fb0d7225f5222bcd0019564ac0ac5f0649e242c7b19299-597d2a846bb8b004ef04143ee27b4f2061367ce1f574db03c0eec66ce3f0654b","complete":true,"records":424644,"lastAttemptAt":"2026-11-12T10:53:33.7939567+00:00","lastSuccessAt":"2026-11-12T10:53:33.7645522+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:53:33.7939567+00:00","snapshotPublishedAt":"2026-11-12T10:28:09+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-9db698e4659747149ec1092e3d34a5a1","complete":true,"records":13764,"lastAttemptAt":"2026-11-12T10:56:11.9015763+00:00","lastSuccessAt":"2026-11-12T09:56:01.656+00:00","error":null,"lastVerifiedAt":"2026-11-12T09:56:01.656+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13817,"expectedIdentifiers":13817,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-12T10:55:30.8237330+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-12T10:55:30.823733+00:00","lastSuccessAt":"2026-11-12T10:55:31.0564011+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:55:31.0564012+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-bd366c4173b74364bb995788ecd92c36","complete":false,"records":13764,"lastAttemptAt":"2026-11-12T10:56:10.5374387+00:00","lastSuccessAt":"2026-11-12T10:56:10.532+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:56:10.532+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13313,"expectedIdentifiers":13817,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-3562b6c78fd1bd0f0b55daf66a0926ae24f65e462df7f6d928caad458fc696bf","complete":true,"records":9947,"lastAttemptAt":"2026-11-12T10:55:30.6813009+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:55:30.6813009+00:00","snapshotPublishedAt":"2026-11-11T03:32:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-456002455e0ab94bb92c95476d4e6d175c104cd594749982afd96c893728ecbc","complete":true,"records":2010,"lastAttemptAt":"2026-11-12T10:53:33.9269183+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:53:33.9269183+00:00","snapshotPublishedAt":"2026-11-11T01:17:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-f46f74c6a30a9b6e4cfb481719c6d35521ebec2d53ebf163223d093ae587eb9d","complete":true,"records":3106,"lastAttemptAt":"2026-11-12T10:55:30.7817941+00:00","lastSuccessAt":"2026-11-12T09:55:31.1176285+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:55:30.7817941+00:00","snapshotPublishedAt":"2026-11-12T09:48:13+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-cafddcfb656ee3e2c62171513201ded79d8731137bd7467a5e566349080db7d4","complete":true,"records":231700,"lastAttemptAt":"2026-11-12T10:55:30.5507315+00:00","lastSuccessAt":"2026-11-12T10:55:29.0211827+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:55:30.5507315+00:00","snapshotPublishedAt":"2026-11-12T10:33:04+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}