Vulnerability · Published May 12, 2026 · Assigned by GitHub_M
CVE-2026-42444NanaZip: Unbounded resource consumption in NanaZip littlefs parser via attacker-controlled BlockCount
Low 3.3
In plain English
A low-severity resource allocation without limits in NanaZip from M2Team. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities).
Official description
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 (as reported)
Weakness: CWE-770 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
References
- https://github.com/M2Team/NanaZip/security/advisories/GHSA-7hqh-mq57-wjmq x_refsource_CONFIRM