{"schemaVersion":3,"id":"CVE-2026-55012","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"Integer overflow or wraparound in Microsoft Defender allows an unauthorized attacker to execute code locally.","dates":{"published":"2026-07-14T17:05:03.730Z","modified":"2026-10-08T18:13:17.092Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.8,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":7.8,"severity":"high","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":7.8,"severity":"high","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00466,"percentile":0.39043,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":0.09200000000000003,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.00374},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00466,"percentile":0.39043}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00374,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00466,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00466,"percentile":0.39043}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-122","name":"Heap-based Buffer Overflow","description":"A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().","type":"weakness","status":"Draft","abstraction":"Variant","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/122.html"},{"id":"CWE-190","name":"Integer Overflow or Wraparound","description":"The product performs a calculation that can\n         produce an integer overflow or wraparound when the logic\n         assumes that the resulting value will always be larger than\n         the original value. This occurs when an integer value is\n         incremented to a value that is too large to store in the\n         associated representation. When this occurs, the value may\n         become a very small or negative number.","type":"weakness","status":"Stable","abstraction":"Base","likelihoodOfExploit":"Medium","url":"https://cwe.mitre.org/data/definitions/190.html"}],"affected":[{"vendor":"microsoft","product":"malware_protection_engine","name":"Malware Protection Engine","label":"malware_protection_engine","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 1.1.26060.3008","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 1.1.26060.3008","eol":null,"hubHref":"/vendor/microsoft/malware_protection_engine"},{"vendor":"microsoft","product":"microsoft malware protection engine","name":"Microsoft Malware Protection Engine","label":"microsoft malware protection engine","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 1.1.0.0, < 1.1.26060.3008","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.1.0.0, < 1.1.26060.3008","eol":null,"hubHref":"/vendor/microsoft/microsoft_malware_protection_engine"}],"affectedCount":2,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55012","label":"msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55012","hostname":"msrc.microsoft.com","tags":["Vendor Advisory","Patch"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-07-14T17:05:03.730Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-10-08T18:13:17.092Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":31,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T20:41:13.500Z","stale":false,"partial":false}}