CVE-2026-55782

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.

CVSS 4.0

2.4CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 5% of CVEs (scores of 2026-10-25)

CWEs

CWE-400, CWE-789

Published

2026-07-10

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

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

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