CVE-2026-20817 | Windows Error Reporting Service Elevation of Privilege Vulnerability

Improper handling of insufficient permissions or privileges in Windows Error Reporting allows an authorized attacker to elevate privileges locally.

Published: 2026-01-13 Last update: 2026-05-26 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-20817 is rated High Risk (67.6/100): CVSS High severity, with high exploitation likelihood (EPSS 4.74%, 91th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +4.64% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

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-2026-20817

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 2026-06-15 0.10% 4.74% +4.64%
2 2026-05-27 0.02% 0.10% +0.08%
3 2026-02-18 — 0.02% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20817

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-2026-20817

GitHub Security Advisory for CVE-2026-20817

GHSA-p4qh-cj7j-r785 · Severity: high — Improper handling of insufficient permissions or privileges in Windows Error Reporting allows an...

Affected software / configurations for CVE-2026-20817

Vendor Product Version Raw CPE
microsoft windows_10_21h2 < 10.0.19044.6809 cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*
microsoft windows_10_22h2 < 10.0.19045.6809 cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*
microsoft windows_11_23h2 < 10.0.22631.6491 cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:*
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_2022 < 10.0.20348.4648 cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
microsoft windows_server_2022_23h2 < 10.0.25398.2092 cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*
microsoft windows_server_2025 < 10.0.26100.32230 cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*

References for CVE-2026-20817

cvelogic Threat Intelligence