A vulnerability in B1 Free Archiver v1.5.86 allows files extracted from downloaded…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-290.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-50328
- 2026-10-03 Alias added: GHSA-vh8g-ch7v-39pg
References
Sources
- CVE-2025-50328 · CVE Program
- CVE-2025-50328 · NVD
- FIRST EPSS
- GHSA-vh8g-ch7v-39pg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences