What’s Vulnerable › Vulnerabilities

CVE-2026-55782: NanaZip: Unbounded memory allocation (DoS) in NanaZip WebAssembly parser via attacker-controlled section/name length fields

• 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-400

Description

NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's WebAssembly archive handler in NanaZip.Codecs.Archive.WebAssembly.cpp allocates buffers from attacker-controlled 32-bit section and custom-name length fields without validating them against the data present in the file. A tiny crafted module can force multi-gigabyte allocations during listing or extraction through NameSize, Information.Size, and std::string or vector allocation paths, causing memory exhaustion or process termination. 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/1ce90f2d14a984476d0407a835273705607facf2
• https://github.com/M2Team/NanaZip/commit/56aee89037947410dd5e66f3a087e0f290484bae
• https://github.com/M2Team/NanaZip/commit/92b12a6e1eb0cf8e88fcc277aa7508ca1ff27db6
• https://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-qxhc-2v6p-wm8m
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-qxhc-2v6p-wm8m

Get alerted when CVE-2026-55782 or the next vulnerability affects your stack