{"id":"CVE-2026-66349","aliases":["EUVD-2026-51340","GHSA-8m3p-4g59-6h2r"],"status":"published","title":"MZ Automation libiec61850 Out-of-bounds Read","description":"The MMS server connection handler contains a flaw in its processing of \nBER-encoded request data. When an MMS confirmed request PDU containing \nan extended BER tag is received over an established session, the decoder\n may advance its internal buffer incorrectly due to a missing bounds \ncheck. This results in a one byte heap out-of-bounds read and causes the\n MMS service process to terminate, leading to a denial-of-service \ncondition.","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00295,"percentile":0.22304,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-125"],"published":"2026-07-30T22:31:32Z","modified":"2026-10-23T23:10:00Z","products":[{"vendor":"mz automation","product":"libiec61850"},{"vendor":"mz automation gmbh","product":"libiec61850"}],"references":[{"url":"https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-10"},{"url":"https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-10.json"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66349"},{"url":"https://github.com/advisories/GHSA-8m3p-4g59-6h2r"}],"sources":{"cve":[{"id":"CVE-2026-66349","title":"MZ Automation libiec61850 Out-of-bounds Read","description":"The MMS server connection handler contains a flaw in its processing of \nBER-encoded request data. When an MMS confirmed request PDU containing \nan extended BER tag is received over an established session, the decoder\n may advance its internal buffer incorrectly due to a missing bounds \ncheck. This results in a one byte heap out-of-bounds read and causes the\n MMS service process to terminate, leading to a denial-of-service \ncondition.","status":"published","published":"2026-07-30T22:31:32.618Z","modified":"2026-07-31T15:54:00.925Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:20:12.939084Z"}],"euvd":[{"id":"EUVD-2026-51340","description":"The MMS server connection handler contains a flaw in its processing of \nBER-encoded request data. When an MMS confirmed request PDU containing \nan extended BER tag is received over an established session, the decoder\n may advance its internal buffer incorrectly due to a missing bounds \ncheck. This results in a one byte heap out-of-bounds read and causes the\n MMS service process to terminate, leading to a denial-of-service \ncondition.","status":"published","published":"2026-07-30T22:31:32Z","modified":"2026-07-31T15:54:00Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:02:25.856077Z"}],"ghsa":[{"id":"GHSA-8m3p-4g59-6h2r","title":"The MMS server connection handler contains a flaw in its processing of \nBER-encoded request data....","description":"The MMS server connection handler contains a flaw in its processing of \nBER-encoded request data. When an MMS confirmed request PDU containing \nan extended BER tag is received over an established session, the decoder\n may advance its internal buffer incorrectly due to a missing bounds \ncheck. This results in a one byte heap out-of-bounds read and causes the\n MMS service process to terminate, leading to a denial-of-service \ncondition.","status":"published","published":"2026-07-31T00:30:22Z","modified":"2026-07-31T00:30:30Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/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:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T15:09:59.725505Z"}],"nvd":[{"id":"CVE-2026-66349","description":"The MMS server connection handler contains a flaw in its processing of \nBER-encoded request data. When an MMS confirmed request PDU containing \nan extended BER tag is received over an established session, the decoder\n may advance its internal buffer incorrectly due to a missing bounds \ncheck. This results in a one byte heap out-of-bounds read and causes the\n MMS service process to terminate, leading to a denial-of-service \ncondition.","status":"published","published":"2026-07-30T23:16:52.92Z","modified":"2026-10-23T23:10:00.157Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/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:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:12:33.955581Z"}]}}