CVE-2026-42444

What it is

NanaZip is an open source file archive. From 5.0.1252.0 to before 6.0.1698.0, a denial-of-service vulnerability exists in the littlefs filesystem image parser in NanaZip. The handler's Open method reads BlockCount directly from the attacker-controlled superblock without any validation against the actual file size or any upper-bound ceiling, then iterates BlockCount times, allocating a file-path entry per iteration. A crafted 44-byte littlefs image with BlockCount = 0xFFFFFFFF causes ~4 billion heap allocations, exhausting available memory. This vulnerability is fixed in 6.0.1698.0.

At a glance

Exploitability

Can be exploited locally on the machine without logging in, but needs a user to act. Limited direct impact.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2026-05-12 20:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-26 18:10 UTC Last updatedMost recent change to the record

Details

Published

2026-05-12 20:16 UTC

Last modified

2026-10-26 18:10 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-770 · Allocation without limits

Record status

Analyzed

Affected

• m2team Nanazip < 6.0.1698.0

Attack profile CVSS 3.1 · 3.3

Attack vector

Local

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low