CVE-2026-55780

LOWCVSS 2.4/10EPSS 0.11%

Last modified

CVE-2026-55780 is a low-severity vulnerability rated 2.4/10 on the CVSS scale. NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's .NET single-file bundle handler in NanaZip.Codecs.Archive.DotNetSingleFile.cpp sizes its extraction buffer from the bundle entry Size field, which is only checked for sign and is not validated against the real file size. EPSS estimates a 0.11% chance of exploitation in the next 30 days.

Description

NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's .NET single-file bundle handler in NanaZip.Codecs.Archive.DotNetSingleFile.cpp sizes its extraction buffer from the bundle entry Size field, which is only checked for sign and is not validated against the real file size. A crafted bundle can cause an attacker-chosen allocation inside Extract, where std::bad_alloc or std::length_error can escape across the COM STDMETHODCALLTYPE boundary and crash the process. This issue is fixed in version 6.5.1749.0.

Metrics

CVSS 4.0
2.4/10

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.11%

1.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
M2TeamNanaZip< 6.5.1749.0

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-55780?
NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's .NET single-file bundle handler in NanaZip.Codecs.Archive.DotNetSingleFile.cpp sizes its extraction buffer from the bundle entry Size field, which is only checked for sign and is not validated against the real file size. A crafted bundle can cause an attacker-chosen allocation inside Extract, where std::bad_alloc or std::length_error can escape across the COM STDMETHODCALLTYPE boundary and crash the process. This issue is fixed in version 6.5.1749.0.
How severe is CVE-2026-55780?
CVE-2026-55780 has a CVSS score of 2.4/10 (LOW severity). The EPSS model estimates a 0.11% probability of exploitation in the next 30 days.
How do I fix CVE-2026-55780?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST