Uncontrolled resource consumption in M2Team NanaZip
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's WebAssembly archive handler in NanaZip.Codecs.Archive.WebAssembly.cpp allocates buffers from attacker-controlled 32-bit section and custom-name length fields without validating them against the data present in the file. A tiny crafted module can force multi-gigabyte allocations during listing or extraction through NameSize, Information.Size, and std::string or vector allocation paths, causing memory exhaustion or process termination. This issue is fixed in version 6.5.1749.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA NanaZip (M2Team) Fixed in 6.5.1749.0
Timeline
- 2026-10-02 Threatist record created from CVE-2026-55782
References
Other 5
- https://github.com/M2Team/NanaZip/security/advisories/GHSA-qxhc-2v6p-wm8m
- https://github.com/M2Team/NanaZip/commit/1ce90f2d14a984476d0407a835273705607facf2
- https://github.com/M2Team/NanaZip/commit/56aee89037947410dd5e66f3a087e0f290484bae
- https://github.com/M2Team/NanaZip/commit/92b12a6e1eb0cf8e88fcc277aa7508ca1ff27db6
- https://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0
More M2Team vulnerabilities
- TI-2026-39447 NanaZip: Heap out-of-bounds read in NanaZip SquashFS LZ4 decompressor via unchecked negative return value CVSS 3.1HIGH 7.1
- TI-2026-32194 NanaZip: Heap out-of-bounds write in NanaZip UFS directory parser CVSS 3.1HIGH 7.1
- TI-2026-34809 NanaZip: Heap out-of-bounds read in NanaZip AVB hashtree descriptor parser via 32-bit unsigned integer overflow CVSS 3.1MEDIUM 5.4
- TI-2026-34808 NanaZip: Heap out-of-bounds read in NanaZip AVB property descriptor parser via unsigned integer underflow CVSS 3.1MEDIUM 5.4
- TI-2026-30733 NanaZip: Unbounded resource consumption in NanaZip littlefs parser via attacker-controlled BlockCount CVSS 3.1MEDIUM 5.5
- TI-2026-21251 NanaZip has DotNet Single file OOB Heap Read CVSS 4.0MEDIUM 5.2
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences