CVE-2026-55782 Denial of service in NanaZip
An attacker can cause memory exhaustion and application crash in NanaZip by crafting a malicious WebAssembly archive with invalid length fields.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-55782?
CVE-2026-55782 is a low-severity denial of service vulnerability in M2Team NanaZip, published on 10 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
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.
Which versions are affected by CVE-2026-55782?
How do I fix CVE-2026-55782?
No fix has been published for CVE-2026-55782 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-55782 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55782 exists.
Sources
Also known as GHSA-qxhc-2v6p-wm8m.