What’s Vulnerable › Vulnerabilities

CVE-2026-55783: NanaZip: NULL pointer dereference in Extract() of all seven NanaZip custom archive handlers when extracting/testing the whole archive

• Severity: low (CVSS 2.4 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-10 · updated 2026-10-25
• Weakness: CWE-476

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.

Affected products

• M2Team NanaZip: before 6.5.1749.0

References

• https://github.com/M2Team/NanaZip/commit/5d74d90b737ac7096e5d944a5a3070c5c6a8f894
• https://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-q67r-9cfh-xc29
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-q67r-9cfh-xc29

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