CVE-2026-55254CWE-190CWE-770denial-of-service

CVE-2026-55254

Medium · published July 18, 2026

CVSS v3.1
4.8
EPSS
0%
Percentile
20.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.8 · MEDIUM
Vector
CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00292 · 20.6th percentile
Weaknesses
CWE-190 · Integer Overflow or Wraparound; CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-07-18T00:17Z
Affected products (1)
ProductVersionsFixed in
ncalc/ncalc< 6.1.16.1.1
References (4)
https://github.com/ncalc/ncalc/commit/eeb6155ee1899b1fdf2cda3da35a4f0ca93ffd6a · [email protected]https://github.com/ncalc/ncalc/pull/575 · [email protected]https://github.com/ncalc/ncalc/releases/tag/v6.1.1 · [email protected]https://github.com/ncalc/ncalc/security/advisories/GHSA-3w5p-95mh-gq75 · [email protected]
EPSS history
Timeline
  • 17 JUL 19:55Z
    NCalc: Denial of Service via Unbounded and Non-Terminating Factorial Evaluation
    cvelistv5