CVE-2026-55781: CWE-400: Uncontrolled Resource Consumption in M2Team NanaZip
CVE-2026-55781 is a low-severity vulnerability in NanaZip, a 7-Zip derivative for Windows. Prior to version 6.5.1749.0, the UFS and FFS image handler improperly validates certain size fields, allowing crafted UFS images to trigger excessive memory allocations. This can cause memory exhaustion or process termination during file open or extraction. The issue is fixed in version 6.5.1749.0.
AI Analysis
Technical Summary
NanaZip versions before 6.5.1749.0 contain an uncontrolled resource consumption vulnerability in the UFS and FFS image handler (NanaZip.Codecs.Archive.Ufs.cpp). The handler validates the superblock block size only against a minimum bound but does not validate the fs_fsize fragment size. This allows attacker-controlled 32-bit fields to influence allocations for indirect blocks, directories, and extraction buffers. A specially crafted UFS image can cause multi-gigabyte memory allocations, leading to memory exhaustion or process termination during file open or extraction. The vulnerability is addressed in version 6.5.1749.0.
Potential Impact
An attacker can supply a maliciously crafted UFS image that triggers excessive memory allocation, potentially exhausting system memory or causing the NanaZip process to terminate unexpectedly. This results in denial of service but does not indicate code execution or data corruption based on the provided data.
Mitigation Recommendations
Upgrade NanaZip to version 6.5.1749.0 or later, where this vulnerability is fixed. No other mitigation or temporary workaround is indicated in the available data.
CVE-2026-55781: CWE-400: Uncontrolled Resource Consumption in M2Team NanaZip
Description
CVE-2026-55781 is a low-severity vulnerability in NanaZip, a 7-Zip derivative for Windows. Prior to version 6.5.1749.0, the UFS and FFS image handler improperly validates certain size fields, allowing crafted UFS images to trigger excessive memory allocations. This can cause memory exhaustion or process termination during file open or extraction. The issue is fixed in version 6.5.1749.0.
CVSS v4.0
Score 2.4low
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
NanaZip versions before 6.5.1749.0 contain an uncontrolled resource consumption vulnerability in the UFS and FFS image handler (NanaZip.Codecs.Archive.Ufs.cpp). The handler validates the superblock block size only against a minimum bound but does not validate the fs_fsize fragment size. This allows attacker-controlled 32-bit fields to influence allocations for indirect blocks, directories, and extraction buffers. A specially crafted UFS image can cause multi-gigabyte memory allocations, leading to memory exhaustion or process termination during file open or extraction. The vulnerability is addressed in version 6.5.1749.0.
Potential Impact
An attacker can supply a maliciously crafted UFS image that triggers excessive memory allocation, potentially exhausting system memory or causing the NanaZip process to terminate unexpectedly. This results in denial of service but does not indicate code execution or data corruption based on the provided data.
Mitigation Recommendations
Upgrade NanaZip to version 6.5.1749.0 or later, where this vulnerability is fixed. No other mitigation or temporary workaround is indicated in the available data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-17T14:40:28.379Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a51295b68715ace43e3b821
Added to database: 07/10/2026, 17:18:19 UTC
Last enriched: 07/10/2026, 17:33:04 UTC
Last updated: 07/10/2026, 19:12:20 UTC
Views: 5
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.