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PatchSiren cyber security CVE debrief

CVE-2026-47222 M2Team CVE debrief

CVE-2026-47222 is a medium-severity vulnerability in NanaZip, a 7-Zip derivative for modern Windows experiences. The issue allows for a heap out-of-bounds read, potentially leading to a denial of service (crash) when opening a crafted .avb or .img file.

Vendor
M2Team
Product
NanaZip
CVSS
MEDIUM 5.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-12
Original CVE updated
2026-06-15
Advisory published
2026-06-12
Advisory updated
2026-06-15

Who should care

Users of NanaZip versions from 3.0.1000.0 to before 6.0.1698.0 should update to the patched version 6.0.1698.0 or later.

Technical summary

The vulnerability exists in the Android Verified Boot (AVB) vbmeta image parser in NanaZip (via the upstream 7-Zip AvbHandler). An unsigned integer underflow in a bounds check allows an attacker-controlled value_num_bytes field to pass validation, causing AddNameToString to read up to ~4 GiB past the end of a 64 KiB heap buffer.

Defensive priority

Medium

Recommended defensive actions

  • Update NanaZip to version 6.0.1698.0 or later.
  • Avoid opening untrusted .avb or .img files.

Evidence notes

The CVE-2026-47222 vulnerability has been patched in stable version 6.0.1698.0 and preview version 6.5.1742.0 of NanaZip.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-47222 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-47222

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-47222 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-47222

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.