NanaZip .NET Single-File Parser Integer Underflow Leads to Unbounded Allocation (DoS)
Published Feb 25, 2026 · Updated Oct 23, 2026
Original summary
Normalized public record · Updated Oct 23, 2026
NanaZip .NET Single-File Parser Integer Underflow Leads to Unbounded Allocation (DoS)
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
NanaZip is an open source file archive. Starting in version 5.0.1252.0 and prior to versions 6.0.1638.0 and 6.5.1638.0, a denial-of-service vulnerability exists in NanaZip’s `.NET Single File Application` parser. A crafted bundle can force an integer underflow in header-size calculation and trigger an unbounded memory allocation attempt during archive open. Versions 6.0.1638.0 and 6.5.1638.0 fix the issue.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- LOW
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Feb 25, 2026 · Last refreshed Oct 23, 2026