CVE-2026-85880
Microsoft Windows 10 Version 1607, Microsoft Windows 10 Version 1809, Microsoft Windows 10 Version 21H2
Published 8 Sept 2026 · updated 24 Sept 2026 · Analyzed
Exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on 8 Sept 2026, with a remediation deadline of 22 Sept 2026 for US federal agencies.
Required action: 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.
Description
Heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally.
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85880 · Patch, Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-85880 · US Government Resource
Covered in The Skim
- You thought patching was bad before? (on The Security Skim)
“Move fast and break things was supposed to be a cautionary tale, not an automated GitHub Action running every forty-five minutes.”