CVE-2026-42446

NanaZip: Stack out-of-bounds read in NanaZip ZealFS bitmap parser

State: Published
Severity: 4.4 Medium
Published: May 12, 2026
Updated: May 13, 2026
Reserved: Apr 27, 2026

Description

NanaZip is an open source file archive. From 5.0.1252.0 to before 6.0.1698.0, a stack-based out-of-bounds read exists in the ZealFS filesystem image parser in NanaZip. The vulnerability is triggered when opening a crafted ZealFS v1 filesystem image. An attacker-controlled BitmapSize field in the file header drives an unbounded loop that reads past the end of a stack-allocated ZEALFS_V1_HEADER structure. This vulnerability is fixed in 6.0.1698.0.

Scores

CVSS	Score	Vector	Source
3.1	4.4 Medium	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L	GitHub_M

Weaknesses

CWE-125 Out-of-bounds Read

Affected Products

Product	Versions
NanaZipM2Team	>= 5.0.1250.0, < 6.0.1698.0Affected

References

https://github.com/M2Team/NanaZip/security/advisories/GHSA-4c79-hfr4-mqv9

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