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: 2026-06-12
Advisory published: 2026-06-12
Advisory updated: 2026-06-12

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.

Official resources

CVE-2026-47222 was published on 2026-06-12T17:16:24.087Z and modified on 2026-06-12T18:16:34.533Z.