CVE-2026-55254

NCalc: Denial of Service via Unbounded and Non-Terminating Factorial Evaluation

Published Jul 17, 2026 CVSS 3.1 · 4.8 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-3w5p-95mh-gq75 NCalc: Denial of Service via Unbounded and Non-Terminating Factorial Evaluation
History
Type Values Removed Values Added
CPEs cpe:2.3:a:ncalc:ncalc:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Ncalc
Ncalc ncalc
Vendors & Products Ncalc
Ncalc ncalc
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title NCalc: Denial of Service via Unbounded and Non-Terminating Factorial Evaluation
Weaknesses CWE-190
CWE-770
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 20, 2026, 6:07 PM
Reserved
Jun 16, 2026, 4:44 PM
Status
Analyzed
Published
Jul 17, 2026, 8:17 PM
Modified
Aug 18, 2026, 3:44 PM