CVE-2026-85880KEV · OVERDUECWE-122CWE-908

Microsoft Windows Heap-Based Buffer Overflow Vulnerability

High · published September 8, 2026

Patch now

Confirmed exploited, and the score agrees

CVSS calls it high at 7.8. It is confirmed in active exploitation. It sits in the 89.5th percentile for exploit probability.

32
days past CISA
deadline
CVSS v3.1
7.8
EPSS
4%
Percentile
89.5
In the wild
Confirmed
What it is

Heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally.

The record
Technical detail
CVSS v3.1
7.8 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.03616 · 89.5th percentile
Weaknesses
CWE-122 · Heap-based Buffer Overflow; CWE-908 · Use of Uninitialized Resource
Published
2026-09-08T22:21Z
KEV added
2026-09-08 · due 2026-09-22
Affected products (15)
ProductVersionsFixed in
microsoft/windows_10_1607< 10.0.14393.951210.0.14393.9512
microsoft/windows_10_1607< 10.0.14393.951210.0.14393.9512
microsoft/windows_10_1809< 10.0.17763.924510.0.17763.9245
microsoft/windows_10_1809< 10.0.17763.924510.0.17763.9245
microsoft/windows_10_21h2< 10.0.19044.772510.0.19044.7725
microsoft/windows_10_21h2< 10.0.19044.772510.0.19044.7725
microsoft/windows_10_21h2< 10.0.19044.772510.0.19044.7725
microsoft/windows_10_22h2< 10.0.19045.772510.0.19045.7725
microsoft/windows_10_22h2< 10.0.19045.772510.0.19045.7725
microsoft/windows_10_22h2< 10.0.19045.772510.0.19045.7725
microsoft/windows_server_2012all versions—
microsoft/windows_server_2012all versions—
microsoft/windows_server_2016< 10.0.14393.951210.0.14393.9512
microsoft/windows_server_2019< 10.0.17763.924510.0.17763.9245
microsoft/windows_server_2022< 10.0.20348.562210.0.20348.5622
References (2)
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85880 · [email protected]https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-85880 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 10 SEP 03:18Z
    EPSS moved — → 1%
    epss
  • 08 SEP 17:14Z
    Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability
    cvelistv5