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TI-2026-40269 Aliases CVE-2026-55780

NanaZip: Uncaught exception / unbounded allocation in NanaZip .NET single-file Extract() via unvalidated entry Size

Priority MEDIUM 46CWE-248Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-248.

Summary

NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's .NET single-file bundle handler in NanaZip.Codecs.Archive.DotNetSingleFile.cpp sizes its extraction buffer from the bundle entry Size field, which is only checked for sign and is not validated against the real file size. A crafted bundle can cause an attacker-chosen allocation inside Extract, where std::bad_alloc or std::length_error can escape across the COM STDMETHODCALLTYPE boundary and crash the process. This issue is fixed in version 6.5.1749.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0056 46th percentileScored 2026-11-07
Fix Fixed NanaZip (M2Team): 6.5.1749.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
M2TeamNanaZipbefore 6.5.1749.06.5.1749.0Patch availableCNA
  • NanaZip VendorM2Team Affected before 6.5.1749.0 Fixed in 6.5.1749.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:m2team:nanazip:*:*:*:*:*:*:*:*——M2Team
  • cpe:2.3:a:m2team:nanazip:*:*:*:*:*:*:*:* Versions — — ·M2Team

Remediation

  • Fix · CNA NanaZip (M2Team) Fixed in 6.5.1749.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-55780

References

Other 3

  • TI-2026-39447 NanaZip: Heap out-of-bounds read in NanaZip SquashFS LZ4 decompressor via unchecked negative return value CVSS 3.1HIGH 7.1
  • TI-2026-32194 NanaZip: Heap out-of-bounds write in NanaZip UFS directory parser CVSS 3.1HIGH 7.1
  • TI-2026-34809 NanaZip: Heap out-of-bounds read in NanaZip AVB hashtree descriptor parser via 32-bit unsigned integer overflow CVSS 3.1MEDIUM 5.4
  • TI-2026-34808 NanaZip: Heap out-of-bounds read in NanaZip AVB property descriptor parser via unsigned integer underflow CVSS 3.1MEDIUM 5.4
  • TI-2026-30733 NanaZip: Unbounded resource consumption in NanaZip littlefs parser via attacker-controlled BlockCount CVSS 3.1MEDIUM 5.5
  • TI-2026-21251 NanaZip has DotNet Single file OOB Heap Read CVSS 4.0MEDIUM 5.2
See all 20 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences