{"id":"CVE-2026-85880","published":"2026-09-08T18:21:14Z","modified":"2026-09-24T23:19:20Z","title":"Microsoft Windows Heap-Based Buffer Overflow Vulnerability","vendor":"Microsoft","product":"Windows","tier":"core","eol":null,"description":{"text":"Heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally.","provenance":"source","from":"NVD"},"summary":{"text":"A heap-based buffer overflow in the Windows ALPC (Advanced Local Procedure Call) component of Microsoft Windows. An attacker who already has an authorized local account on the system can exploit it to elevate privileges, requiring no user interaction and only low attack complexity.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:07Z"},"cvss":{"score":7.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.00387,"percentile":0.3281,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2026-09-08","dueDate":"2026-09-22","ransomware":false,"requiredAction":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","notes":"https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-85880 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-85880","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-09-08","exploitedFirstSeen":"2026-09-08","ransomware":false,"evidence":[{"url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2026-Sep","date":"2026-09-08"},{"url":"https://euvd.enisa.europa.eu/enisa/EUVD-2026-73365","date":"2026-09-08"},{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85880","date":"2026-09-08"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-09-08"},{"url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","date":"2026-09-09"},{"url":"https://www.volexity.com/blog/2026/09/09/mind-the-patch-gap-multiple-chinese-threat-actors-chain-0-day-exploits-in-chrome-windows/","date":"2026-09-09"},{"url":"https://www.proofpoint.com/us/blog/threat-insight/once-bluemoon-multiple-state-aligned-threat-actors-rapidly-adopt-novel-exploit","date":"2026-09-14"},{"url":"https://www.volexity.com/blog/2026/09/21/mind-the-patch-gap-part-2-fake-websites-used-to-deploy-chrome-windows-0-day-exploits/","date":"2026-09-21"}],"evidenceTotal":8,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 31, 2026","url":"https://otx.alienvault.com/pulse/6ae4aefab0c2191cecd41862","created":"2026-10-30"},{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"}],"provenance":"machine"},"cwes":[{"id":"CWE-122","name":"Heap-based Buffer Overflow"},{"id":"CWE-908","name":"Use of Uninitialized Resource"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85880","tags":["Patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-85880","tags":["US Government Resource"]}],"techniques":[{"id":"T1068","name":"Exploitation for Privilege Escalation","tactics":["privilege-escalation"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: local privilege escalation via heap overflow","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"allows an authorized attacker to elevate privileges locally","start":43,"end":102}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1055","name":"Process Injection","tactics":["privilege-escalation","stealth"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: memory corruption enables process injection","mappingType":"primary_impact","evidence":[{"from":"description","quote":"Heap-based buffer overflow in Windows ALPC","start":0,"end":42}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2026-73365","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-73365","exploited":true,"exploitedSince":"2026-09-08","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1068"],"provenance":"ai"},{"stage":"primary","techniques":["T1055"],"provenance":"ai"}],"timeline":[{"date":"2026-09-08","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-85880","provenance":"source"},{"date":"2026-09-08","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2026-Sep","provenance":"source"},{"date":"2026-09-08","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2026-09-08","kind":"euvd-exploited","label":"ENISA EUVD: 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