Riskcovery

CVE-2026-55781

NanaZip: Unbounded memory allocation (DoS) in NanaZip UFS parser via unvalidated fs_bsize/fs_fsize superblock fields

State
Published
Severity
2.4 Low
Published
Jul 10, 2026
Updated
Jul 10, 2026
Reserved
Jun 17, 2026

Read the record on cve.org

Description

NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's UFS and FFS image handler in NanaZip.Codecs.Archive.Ufs.cpp validates the superblock block size only against the MINBSIZE lower bound and does not validate the fs_fsize fragment size, allowing attacker-controlled 32-bit fields to flow into indirect-block, directory, and extraction buffer allocations. A tiny crafted UFS image can force multi-gigabyte allocations during open or extraction, causing memory exhaustion or process termination. This issue is fixed in version 6.5.1749.0.

Scores

CVSSScoreVectorSource
4.02.4 LowCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-400 Uncontrolled Resource Consumption
  • CWE-789 Memory Allocation with Excessive Size Value

Affected Products

ProductVersions
NanaZipM2Team
  • < 6.5.1749.0Affected

References

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