CVE Catalog

CVE-2026-55254

MediumCVSS 4.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.19%

8th percentile - higher than 8% of all known CVEs

Summary

NCalc before version 6.1.1 has a vulnerability in the factorial operator implementation. Specially crafted expressions with extremely large factorial operands cause excessive CPU consumption or a non-terminating loop due to integer overflow when evaluating untrusted expressions.

Risk Assessment

An attacker can cause a denial of service by sending an expression with a very large factorial, leading to CPU exhaustion or application hang.

Recommendation

Upgrade NCalc to version 6.1.1.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS