CVE-2026-55254

MEDIUM

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

Title source: cna
STIX 2.1

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.

References (4)

Core 4

Scores

CVSS v3 4.8
EPSS 0.0019
EPSS Percentile 8.5%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-190 CWE-770
Status published
Products (1)
ncalc/ncalc < 6.1.1
Published Jul 17, 2026
Tracked Since Jul 18, 2026