CVE-2026-55783 Details
Description
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.
A NULL pointer dereference vulnerability has been identified in NanaZip, a 7-Zip derivative, in versions prior to 6.5.1749.0. The issue arises in all seven of NanaZip's custom archive handlers, where the 'Extract' function unconditionally dereferences a caller-supplied 'Indices' array. This occurs when the archive engine indicates to extract everything by passing 'Indices' as NULL and 'NumItems' as 0xFFFFFFFF', leading to a process crash. The vulnerability is triggered by opening an affected archive format and performing a full extraction or test, which is the default behavior in both the command-line interface and common graphical user interface flows.
Users can upgrade to NanaZip version 6.5.1749.0 or later to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 10, 2026CISA-ADP
Assessed Jul 10, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/M2Team/NanaZip/security/advisories/GHSA-q67r-9cfh-xc29 | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/M2Team/NanaZip/commit/5d74d90b737ac7096e5d944a5a3070c5c6a8f894 | [email protected] | Source CodeVendor |
| https://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0 | [email protected] | Release NotesVendor |
| https://github.com/M2Team/NanaZip/security/advisories/GHSA-q67r-9cfh-xc29 | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-476 | NULL Pointer Dereference | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| M2Team NanaZip | <= 6.5 Preview (6.5.1742.0) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 10, 2026 | CVE Modified | CISA-ADP |
| Jul 10, 2026 | New CVE Received | [email protected] |