NanaZip: Null-pointer dereference in NanaZip UFS parser when root inode is a symlink

NanaZip is an open source file archive. From 5.0.1252.0 to before 6.0.1698.0, a null-pointer dereference exists in the UFS/UFS2 filesystem image parser in NanaZip. The vulnerability is triggered when opening a crafted UFS image where the root inode (inode 2) is set to IFLNK (symlink) instead of IFDIR (directory). The parser unconditionally treats the root inode as a directory without checking its type, and when the symlink has an embedded target (small di_size), the directory data buffer is zero-length, causing a null-pointer dereference on the first read. This vulnerability is fixed in 6.0.1698.0.

Problem type

CWE-476: NULL Pointer Dereference

Affected products

M2Team

NanaZip

>= 5.0.1250.0, < 6.0.1698.0 - AFFECTED

References

https://github.com/M2Team/NanaZip/security/advisories/GHSA-8r4x-fx3w-ph77

https://github.com/M2Team/NanaZip/security/advisories/GHSA-8r4x-fx3w-ph77

x_refsource_CONFIRM

JSON source

https://cveawg.mitre.org/api/cve/CVE-2026-42442

Click to expand

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    "assignerShortName": "GitHub_M",
    "dateUpdated": "2026-05-12T19:21:04.924Z",
    "dateReserved": "2026-04-27T13:55:58.692Z",
    "datePublished": "2026-05-12T19:21:04.924Z",
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      },
      "title": "NanaZip: Null-pointer dereference in NanaZip UFS parser when root inode is a symlink",
      "descriptions": [
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          "value": "NanaZip is an open source file archive. From 5.0.1252.0 to before 6.0.1698.0, a null-pointer dereference exists in the UFS/UFS2 filesystem image parser in NanaZip. The vulnerability is triggered when opening a crafted UFS image where the root inode (inode 2) is set to IFLNK (symlink) instead of IFDIR (directory). The parser unconditionally treats the root inode as a directory without checking its type, and when the symlink has an embedded target (small di_size), the directory data buffer is zero-length, causing a null-pointer dereference on the first read. This vulnerability is fixed in 6.0.1698.0."
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