Microsoft Windows Heap-Based Buffer Overflow Vulnerability (CVE-2026-85880)
Severity: high · Patch status: patched · Since 2026-09-08 · CVE-2026-85880
Microsoft Windows Advanced Local Procedure Call contains a heap-based buffer overflow vulnerability that allows an attacker to elevate privileges locally. CISA added CVE-2026-85880 to its Known Exploited Vulnerabilities catalog on Sep 8, 2026, which means attackers are exploiting it in the wild.
What to do
- 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.
- US federal agencies must remediate by Sep 22, 2026 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch
