Process crash via unbounded UFS allocations
Published Jul 10, 2026 · Updated Jul 10, 2026
Uncontrolled resource consumption in NanaZip before 6.5.1749.0 allows local users to crash the process with a crafted UFS image. The UFS/FFS handler in NanaZip.Codecs.Archive.Ufs.cpp accepts unbounded fs_bsize and unchecked fs_fsize fields, then uses derived sizes for indirect-block, directory, and extraction buffers. Browsing or extracting the image is sufficient to trigger multi-gigabyte allocation attempts, causing memory exhaustion or process termination.
Summary
What happened
Uncontrolled resource consumption in NanaZip before 6.5.1749.0 allows local users to crash the process with a crafted UFS image. The UFS/FFS handler in NanaZip.Codecs.Archive.Ufs.cpp accepts unbounded fs_bsize and unchecked fs_fsize fields, then uses derived sizes for indirect-block, directory, and extraction buffers. Browsing or extracting the image is sufficient to trigger multi-gigabyte allocation attempts, causing memory exhaustion or process termination.
The record
- CVE
- CVE-2026-55781
- Published
- Jul 10, 2026
- Updated
- Jul 10, 2026
- Vendor
- M2-Team
- Product
- NanaZip
- Classifications
- CWE-400, CWE-789
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 10, 2026CVE publishedPublication date reported by the CVE source.
- Jul 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 6.5.1749.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- NanaZip UFS excessive-allocation PoC generatorproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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