CVE-2026-55254
Medium
Description
NCalc is a fast, lightweight expression evaluator for .NET. Prior to 6.1.1, the factorial operator implementation in src/NCalc.Core/Helpers/MathHelper.cs permits specially crafted expressions with extremely large factorial operands, causing excessive CPU consumption or a non-terminating loop due to integer overflow in the factorial calculation logic when applications evaluate untrusted expressions. This issue is fixed in version 6.1.1.
SeverityMedium
CVSS4.8
Exploit probability—
ProductNcalc
PublishedJul 17, 2026
First seenJul 17, 2026
How to fix
Update
- ncalc ncalc6.1.1 or later
- NCalc.Core6.1.1 or later
- NCalcSync6.1.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| ncalc ncalc | v < 6.1.1 | 6.1.1 |
| NCalc.CoreNuGet | v < 6.1.1 | 6.1.1 |
| NCalcSyncNuGet | v < 6.1.1 | 6.1.1 |
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