CVE-2025-50328Public exploitNetwork attack vector

SmartScreen warning bypass via omitted MotW propagation

Published Apr 29, 2026 · Updated Apr 29, 2026

Security feature bypass in B1 Free Archiver 1.5.86 allows attackers to run downloaded files without Mark of the Web warnings. During archive extraction, the application fails to copy the source archive's Zone.Identifier alternate data stream to extracted files, causing Windows to treat them as trusted. Exploitation requires a user to download a crafted archive, extract it with the application, and launch a payload; the bypass suppresses the normal SmartScreen warning rather than executing content during extraction.

CVSS severity7.3
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Security feature bypass in B1 Free Archiver 1.5.86 allows attackers to run downloaded files without Mark of the Web warnings. During archive extraction, the application fails to copy the source archive's Zone.Identifier alternate data stream to extracted files, causing Windows to treat them as trusted. Exploitation requires a user to download a crafted archive, extract it with the application, and launch a payload; the bypass suppresses the normal SmartScreen warning rather than executing content during extraction.

The record

CVE
CVE-2025-50328
Published
Apr 29, 2026
Updated
Apr 29, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-290, T1204.002, T1553.005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
T1204.002Malicious File
T1553.005Mark-of-the-Web Bypass

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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