VDB-357385 · CVE-2026-0390 · GCVE-0-2026-0390

Microsoft Windows up to Server 2022 UEFI Secure Boot reliance on untrusted inputs in a security decision

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.8	$5k-$25k	0.86

Summaryinfo

A vulnerability was found in Microsoft Windows up to Server 2022. It has been rated as critical. The affected element is an unknown function of the component UEFI Secure Boot. This manipulation causes reliance on untrusted inputs in a security decision. This vulnerability is registered as CVE-2026-0390. The attack needs to be launched locally. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Microsoft Windows up to Server 2022 and classified as critical. Affected by this vulnerability is an unknown function of the component UEFI Secure Boot. The manipulation with an unknown input leads to a reliance on untrusted inputs in a security decision vulnerability. The CWE definition for the vulnerability is CWE-807. The product uses a protection mechanism that relies on the existence or values of an input, but the input can be modified by an untrusted actor in a way that bypasses the protection mechanism. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was published 04/14/2026 as confirmed security update guide (Website). The advisory is shared at msrc.microsoft.com. This vulnerability is known as CVE-2026-0390. The exploitation appears to be easy. An attack has to be approached locally. The exploitation requires an enhanced level of successful authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 04/14/2026).

Upgrading to version 10.0.14393.9060, 10.0.17763.8644, 10.0.19044.7184, 10.0.19045.7184 or 10.0.20348.5020 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

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Productinfo

Type

Operating System

Vendor

Microsoft

Name

Windows

Version

License

commercial

Website

Vendor: https://www.microsoft.com/
Product: https://www.microsoft.com/en-us/windows

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.7
VulDB Meta Temp Score: 5.8

VulDB Base Score: 6.7
VulDB Temp Score: 5.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 6.7
Vendor Vector (Microsoft): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Reliance on untrusted inputs in a security decision
CWE: CWE-807 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Unproven
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Upgrade: Windows 10.0.14393.9060/10.0.17763.8644/10.0.19044.7184/10.0.19045.7184/10.0.20348.5020

Timelineinfo

04/14/2026 VulDB entry created
04/14/2026 +0 days Advisory disclosed
04/14/2026 +0 days Countermeasure disclosed
04/14/2026 +0 days VulDB entry last update