MediumPublic exploit

Mark-of-the-Web bypass in 7-Zip RAR5 extraction

IdentifiersCVE-2026-58052CWE-59

CVE-2026-58052 is a Mark-of-the-Web preservation flaw in 7-Zip for Windows affecting versions through 26.01, and described in advisory context as through 26.02. When extracting a crafted RAR5 archive, 7-Zip attempts to block archive-supplied NTFS alternate data streams intended to replace the propagated Zone.Identifier stream, but its guard only matches the exact stream name "Zone.Identifier". A malicious RAR5 STM record named in a form that NTFS canonicalizes to the same alternate data stream is not matched by the guard and is therefore written as Zone.Identifier, overwriting the Internet-zone marker with a local-zone value. A second crafted STM record can also overwrite the extracted file's default data stream, allowing the attacker to replace the visible file contents after extraction. The issue enables bypass of Windows Mark-of-the-Web and SmartScreen trust signaling for files extracted from attacker-controlled RAR5 archives.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an attacker to defeat Mark-of-the-Web propagation on extracted files, suppressing or weakening SmartScreen and related Windows security warnings that would normally apply to content originating from the Internet. The attacker can also spoof the extracted file's contents by overwriting the default data stream, creating a mismatch between user expectations and the actual payload delivered after extraction. This increases the likelihood of successful delivery and execution of malicious content and can facilitate initial access or user-assisted code execution.

Mitigation

If you can’t patch tonight, do this now.

Do not extract untrusted or externally sourced RAR5 archives with affected 7-Zip for Windows installations. Prefer alternative archive extraction tools that correctly preserve Mark-of-the-Web semantics, or extract such archives in isolated environments. Apply application control, attachment sandboxing, and endpoint detection controls to inspect extracted content independently of SmartScreen or Zone.Identifier state. Where possible, verify the presence and correctness of Mark-of-the-Web metadata on extracted files before execution.

Remediation

Patch, then assume compromise.

Upgrade 7-Zip for Windows to a fixed version newer than the affected releases once available from the vendor. If an official fix is not yet deployed in the environment, avoid using affected 7-Zip versions to extract untrusted RAR5 archives. Validate extracted files with tooling that correctly preserves or inspects Mark-of-the-Web metadata and use endpoint security controls that do not rely solely on Zone.Identifier for trust decisions.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

7-Zip7-Zipapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

7 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

7 SOURCESView more in app

infosecurity magazine newsNews

Jul 2, 2026

Researcher Explains Release of Undisclosed Zero-Day Exploits - Infosecurity Magazine

A vulnerability in 7-Zip where Mark-of-the-Web warnings are not preserved when extracting crafted RAR5 archives.

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity6

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2026-58052

NVD

nvd.nist.gov/vuln/detail/CVE-2026-58052

MITRE CWE · CWE-59

cwe.mitre.org

Third Party Advisory

vulncheck.com/advisories/7-zip-mark-of-the-web-bypass-via-rar5-alternate-data-stream-name-collision

Product

github.com/ip7z/7zip

Mark-of-the-Web bypass in 7-Zip RAR5 extraction

IdentifiersCVE-2026-58052CWE-59