Inefficient Algorithmic Complexity Affecting microsoft.netcore.app.runtime.linux-musl-arm package, versions [11.0.0-preview.1.26104.118,11.0.0)


Severity

Recommended
0.0
medium
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
1.17% (68th percentile)

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  • Snyk IDSNYK-DOTNET-MICROSOFTNETCOREAPPRUNTIMELINUXMUSLARM-22409062
  • published11 Nov 2026
  • disclosed10 Nov 2026
  • creditArtur Stetsko

Introduced: 10 Nov 2026

NewCVE-2026-120796  (opens in a new tab)
CWE-407  (opens in a new tab)

How to fix?

Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to version 11.0.0 or higher.

Overview

Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in the CreateExtensionDataProperty method in JsonSerializer.Read.HandlePropertyName.cs, which copies the entire existing extension data dictionary into a newly allocated Dictionary even when the existing instance is already a mutable Dictionary. An attacker can force quadratic time and allocation during deserialization by sending an object with a large number of unmapped properties, because LookupProperty invokes the method once per unmapped property and the dictionary being copied grows by one entry each time. Exploitation requires the target type to declare a [JsonExtensionData] property typed IReadOnlyDictionary<string, object> or IReadOnlyDictionary<string, JsonElement>, and that property to be instantiated before deserialization begins, since the copy is skipped when the existing value is null.

CVSS Base Scores

version 4.0
version 3.1