CVE-2026-55780

What it is

NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's .NET single-file bundle handler in NanaZip.Codecs.Archive.DotNetSingleFile.cpp sizes its extraction buffer from the bundle entry Size field, which is only checked for sign and is not validated against the real file size. A crafted bundle can cause an attacker-chosen allocation inside Extract, where std::bad_alloc or std::length_error can escape across the COM STDMETHODCALLTYPE boundary and crash the process. This issue is fixed in version 6.5.1749.0.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account, but needs a user to act. Limited direct impact.

Exploit odds

0.6% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-10 17:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-25 15:10 UTC Last updatedMost recent change to the record

Details

Published

2026-07-10 17:16 UTC

Last modified

2026-10-25 15:10 UTC

Exploit probability

0.6% · EPSS, next 30 days

Weakness

CWE-248

Record status

Deferred

Attack profile CVSS 4.0 · 2.4

Attack vector

Local

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

Passive

Confidentiality

None

Integrity

None

Availability

Low