Vulnerability · Published Jul 10, 2026 · Assigned by GitHub_M

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

Low 2.4

In plain English

A low-severity uncontrolled resource consumption in NanaZip from M2Team. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).

Severity (CVSS 4.0)2.4Low

Exploit odds (30 days)0.2%top 92.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
M2Team	NanaZip	< 6.5.1749.0

Weakness: CWE-400, CWE-789 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

https://github.com/M2Team/NanaZip/security/advisories/GHSA-qxhc-2v6p-wm8m x_refsource_CONFIRM
https://github.com/M2Team/NanaZip/commit/1ce90f2d14a984476d0407a835273705607facf2 x_refsource_MISC
https://github.com/M2Team/NanaZip/commit/56aee89037947410dd5e66f3a087e0f290484bae x_refsource_MISC
https://github.com/M2Team/NanaZip/commit/92b12a6e1eb0cf8e88fcc277aa7508ca1ff27db6 x_refsource_MISC
https://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0 x_refsource_MISC