CVE-2025-50328

ANALYSIS PENDING

B1 Free Archiver 1.5.86 - Auth Bypass

Title source: llm
STIX 2.1

Description

A vulnerability in B1 Free Archiver v1.5.86 allows files extracted from downloaded archives to bypass Windows Mark of the Web (MotW) protections. When an archive is downloaded from the internet and extracted using B1 Free Archiver, the software fails to propagate the 'Zone.Identifier' alternate data stream to the extracted files. As a result, these files can be executed without triggering Windows Defender SmartScreen warnings or security prompts, enabling untrusted code execution without standard security restrictions.

Scores

EPSS 0.0002
EPSS Percentile 5.2%

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

Status published
Published Apr 29, 2026
Tracked Since Apr 30, 2026