CVE-2026-55783: CWE-476: NULL Pointer Dereference in M2Team NanaZip
CVE-2026-55783 is a NULL pointer dereference vulnerability in NanaZip, a 7-Zip derivative for Windows. Versions prior to 6.5.1749.0 have a flaw in seven internal IInArchive handlers that unconditionally dereference a caller-supplied Indices array during extraction when the archive engine signals extraction of all items by passing Indices as NULL and NumItems as 0xFFFFFFFF. This leads to a process crash when handling certain archive types. The issue is fixed in version 6.5.1749.0.
AI Analysis
Technical Summary
NanaZip versions before 6.5.1749.0 contain a NULL pointer dereference vulnerability (CWE-476) in seven in-house IInArchive handlers within NanaZip.Codecs. When the archive engine requests extraction of all items by passing a NULL Indices pointer and a NumItems value of 0xFFFFFFFF, the handlers dereference the NULL pointer unconditionally. This affects archive formats including WebAssembly, ElectronAsar, Zealfs, Romfs, Ufs, Littlefs, and DotNetSingleFile, causing a process crash during standard Test archive or Extract all operations. The vulnerability is resolved in version 6.5.1749.0.
Potential Impact
The vulnerability causes a NULL pointer dereference leading to a process crash when extracting or testing certain archive types. This results in denial of service (application crash) but does not indicate code execution or data corruption. The CVSS 4.0 base score is 2.4, reflecting low severity with local attack vector and limited privileges required.
Mitigation Recommendations
Upgrade NanaZip to version 6.5.1749.0 or later, where this NULL pointer dereference issue is fixed. No other mitigation or workaround is indicated.
CVE-2026-55783: CWE-476: NULL Pointer Dereference in M2Team NanaZip
Description
CVE-2026-55783 is a NULL pointer dereference vulnerability in NanaZip, a 7-Zip derivative for Windows. Versions prior to 6.5.1749.0 have a flaw in seven internal IInArchive handlers that unconditionally dereference a caller-supplied Indices array during extraction when the archive engine signals extraction of all items by passing Indices as NULL and NumItems as 0xFFFFFFFF. This leads to a process crash when handling certain archive types. The issue is fixed in version 6.5.1749.0.
CVSS v4.0
Score 2.4low
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
NanaZip versions before 6.5.1749.0 contain a NULL pointer dereference vulnerability (CWE-476) in seven in-house IInArchive handlers within NanaZip.Codecs. When the archive engine requests extraction of all items by passing a NULL Indices pointer and a NumItems value of 0xFFFFFFFF, the handlers dereference the NULL pointer unconditionally. This affects archive formats including WebAssembly, ElectronAsar, Zealfs, Romfs, Ufs, Littlefs, and DotNetSingleFile, causing a process crash during standard Test archive or Extract all operations. The vulnerability is resolved in version 6.5.1749.0.
Potential Impact
The vulnerability causes a NULL pointer dereference leading to a process crash when extracting or testing certain archive types. This results in denial of service (application crash) but does not indicate code execution or data corruption. The CVSS 4.0 base score is 2.4, reflecting low severity with local attack vector and limited privileges required.
Mitigation Recommendations
Upgrade NanaZip to version 6.5.1749.0 or later, where this NULL pointer dereference issue is fixed. No other mitigation or workaround is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-17T14:40:28.379Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a51295c68715ace43e3b82d
Added to database: 07/10/2026, 17:18:20 UTC
Last enriched: 07/10/2026, 17:32:54 UTC
Last updated: 07/10/2026, 18:14:24 UTC
Views: 7
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