CVE-2026-20870 | Windows Win32 Kernel Subsystem Elevation of Privilege Vulnerability

Use after free in Windows Win32K - ICOMP allows an authorized attacker to elevate privileges locally.

Published: 2026-01-13 Last update: 2026-01-15 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-20870 is rated Low Risk (36.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-20870

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-15 0.03% 0.05% +0.02%
2 2026-02-18 0.06% 0.03% -0.03%
3 2026-02-14 — 0.06% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20870

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2026-20870

Affected software / configurations for CVE-2026-20870

Vendor Product Version Raw CPE
microsoft windows_11_24h2 < 10.0.26100.7623 cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:*
microsoft windows_11_25h2 < 10.0.26200.7623 cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:*:*
microsoft windows_server_2025 < 10.0.26100.32230 cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*

References for CVE-2026-20870

cvelogic Threat Intelligence