A vulnerability in B1 Free Archiver v1.5.86 allows files extracted from downloaded archives to...

CVE-2025-50328 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

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.

Basic information

Type
unreviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
—
Source code
Not specified
Published (advisory)
2026-04-29 21:31:31 UTC
Updated
2026-04-30 15:31:40 UTC
NVD published
2026-04-29

EPSS Score

Score Percentile
0.02% 5.18%

CVSS Scores

Base score Version Severity Vector
7.3 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.

Identifiers

Type Value
GHSA GHSA-vh8g-ch7v-39pg ↗
CVE CVE-2025-50328 ↗

CWEs

CWE id Name
CWE-290 Authentication Bypass by Spoofing

References

cvelogic Threat Intelligence