Zero-day vulnerability in Windows

Improper verification of cryptographic signature
CVE-2025-47827

Vulnerability details

Advisory: SB2025101463 - IGEL OS Secure Boot bypass in Microsoft Windows

Vulnerable component: Windows

CVE-ID: CVE-2025-47827

CVSSv3 score: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

Description:

The vulnerability allows an attacker to bypass implemented security restrictions.

The vulnerability exists due to improper verification of cryptographic signature when mounting a SquashFS image in IGEL OS firmware. An attacker with physical access to the system can bypass Secure Boot protection feature and compromise the affected system.

Note, the vulnerability is being actively exploited in the wild against the Windows users. 

External links:

https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2025-47827

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.