M2Team NanaZip up to 6.5.1748.0 IInArchive Extract Indices/NumItems null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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2.7$0-$5k0.00+

Summaryinfo

A vulnerability was found in M2Team NanaZip up to 6.5.1748.0. It has been classified as problematic. This issue affects the function Extract of the component IInArchive Handler. This manipulation of the argument Indices/NumItems causes null pointer dereference. This vulnerability is tracked as CVE-2026-55783. The attack is restricted to local execution. No exploit exists.

Detailsinfo

A vulnerability was found in M2Team NanaZip up to 6.5.1748.0. It has been declared as problematic. Affected by this vulnerability is the function Extract of the component IInArchive Handler. The manipulation of the argument Indices/NumItems with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's seven in-house IInArchive handlers in NanaZip.Codecs unconditionally dereference the caller-supplied Indices array inside Extract when the archive engine signals extract everything by passing Indices as NULL and NumItems as 0xFFFFFFFF. This causes a NULL pointer dereference in the standard Test archive or Extract all code path for WebAssembly, ElectronAsar, Zealfs, Romfs, Ufs, Littlefs, and DotNetSingleFile archives, resulting in a process crash. This issue is fixed in version 6.5.1749.0.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-55783 since 06/17/2026. The exploitation appears to be easy. An attack has to be approached locally. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

Upgrading to version 6.5.1749.0 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 2.8
VulDB Meta Temp Score: 2.7

VulDB Base Score: 2.8
VulDB Temp Score: 2.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: NanaZip 6.5.1749.0

Timelineinfo

06/17/2026 CVE reserved
07/10/2026 +23 days Advisory disclosed
07/10/2026 +0 days VulDB entry created
07/10/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-55783 (🔒)
GCVE (CVE): GCVE-0-2026-55783
GCVE (VulDB): GCVE-100-377557

Entryinfo

Created: 07/10/2026 19:37
Changes: 07/10/2026 19:37 (55)
Complete: 🔍
Cache ID: 216::103

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