CVE-2026-42444: m2team Nanazip

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

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.

Affected products

• m2team Nanazip: from 5.0.1252.0, before 6.0.1698.0 (fixed in 6.0.1698.0)

Published 2026-05-12. Last modified 2026-06-17.