CVE-2017-0256

Moderate severity vulnerability that affects Microsoft.AspNetCore.Mvc

5.3 MediumFix available

A spoofing vulnerability exists when the ASP.NET Core fails to properly sanitize web requests.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: Low
Availability: None

Exploit likelihood

3.54%Down 1.3 points since Apr 14, 2021

What each source reports

NVD Score used 5.3

A spoofing vulnerability exists when the ASP.NET Core fails to properly sanitize web requests.

Record: CVE-2017-0256
CVSS 3.0: 5.3 MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:P/A:N
Weakness: CWE-20
Updated: 2026-11-02

CVE List No score

A spoofing vulnerability exists when the ASP.NET Core fails to properly sanitize web requests.

Record: CVE-2017-0256
Updated: 2026-11-02

EUVDEUVD-2018-0627 No score

A spoofing vulnerability exists when the ASP.NET Core fails to properly sanitize web requests.

Record: EUVD-2018-0627
Updated: 2026-11-03

GitHub AdvisoriesGHSA-j8f4-2w4p-mhjc 5.3

Moderate severity vulnerability that affects Microsoft.AspNetCore.Mvc

A spoofing vulnerability exists when the ASP.NET Core fails to properly sanitize web requests.

Record: GHSA-j8f4-2w4p-mhjc
CVSS 3.0: 5.3 MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness: CWE-20
Updated: 2026-11-02

OSVGHSA-j8f4-2w4p-mhjc 5.3

Moderate severity vulnerability that affects Microsoft.AspNetCore.Mvc

A spoofing vulnerability exists when the ASP.NET Core fails to properly sanitize web requests.

Record: GHSA-j8f4-2w4p-mhjc
CVSS 3.0: 5.3 MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness: CWE-20
Updated: 2026-11-02

Affected products

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Affected packages

Affected packages
Package	Affected	Fixed
`Microsoft.AspNetCore.Mvc` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.Core` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.Core` NuGet	1.1.0 up to 1.1.3	1.1.3
`System.Net.Http` NuGet	4.1.1 to 4.1.1	4.1.2
`System.Net.Http` NuGet	4.3.1 to 4.3.1	4.3.2
`System.Text.Encodings.Web` NuGet	4.0.0 to 4.0.0	4.0.1
`System.Text.Encodings.Web` NuGet	4.3.0 to 4.3.0	4.3.1
`System.Net.Http.WinHttpHandler` NuGet	4.0.0 to 4.0.0	4.0.1
`System.Net.Http.WinHttpHandler` NuGet	4.3.0 to 4.3.0	4.3.1

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Affected packages
Package	Affected	Fixed
`System.Net.Security` NuGet	4.0.0 to 4.0.0	4.0.1
`System.Net.Security` NuGet	4.3.0 to 4.3.0	4.3.1
`System.Net.WebSockets.Client` NuGet	4.0.0 to 4.0.0	4.0.1
`System.Net.WebSockets.Client` NuGet	4.3.0 to 4.3.0	4.3.1
`Microsoft.AspNetCore.Mvc.Abstractions` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.Abstractions` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.ApiExplorer` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.ApiExplorer` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.Cors` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.Cors` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.DataAnnotations` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.DataAnnotations` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.Formatters.Json` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.Formatters.Json` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.Formatters.Xml` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.Formatters.Xml` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.Localization` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.Localization` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.Razor.Host` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.Razor.Host` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.Razor` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.Razor` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.TagHelpers` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.TagHelpers` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.ViewFeatures` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.ViewFeatures` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc.WebApiCompatShim` NuGet	1.0.0 up to 1.0.4	1.0.4
`Microsoft.AspNetCore.Mvc.WebApiCompatShim` NuGet	1.1.0 up to 1.1.3	1.1.3
`Microsoft.AspNetCore.Mvc` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.Core` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.Core` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`System.Net.Http` NuGet	4.1.1 up to 4.1.2	4.1.2
`System.Net.Http` NuGet	4.3.1 up to 4.3.2	4.3.2
`System.Text.Encodings.Web` NuGet	4.0.0 up to 4.0.1	4.0.1
`System.Text.Encodings.Web` NuGet	4.3.0 up to 4.3.1	4.3.1
`System.Net.Http.WinHttpHandler` NuGet	4.0.0 up to 4.0.1	4.0.1
`System.Net.Http.WinHttpHandler` NuGet	4.3.0 up to 4.3.1	4.3.1
`System.Net.Security` NuGet	4.0.0 up to 4.0.1	4.0.1
`System.Net.Security` NuGet	4.3.0 up to 4.3.1	4.3.1
`System.Net.WebSockets.Client` NuGet	4.0.0 up to 4.0.1	4.0.1
`System.Net.WebSockets.Client` NuGet	4.3.0 up to 4.3.1	4.3.1
`Microsoft.AspNetCore.Mvc.Abstractions` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.Abstractions` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.ApiExplorer` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.ApiExplorer` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.Cors` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.Cors` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.DataAnnotations` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.DataAnnotations` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.Formatters.Json` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.Formatters.Json` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.Formatters.Xml` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.Formatters.Xml` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.Localization` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.Localization` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.Razor.Host` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.Razor.Host` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.Razor` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.Razor` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.TagHelpers` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.TagHelpers` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.ViewFeatures` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.ViewFeatures` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3
`Microsoft.AspNetCore.Mvc.WebApiCompatShim` NuGet	1.0.0 up to 1.0.4, plus listed versions 1.0.11.0.21.0.3	1.0.4
`Microsoft.AspNetCore.Mvc.WebApiCompatShim` NuGet	1.1.0 up to 1.1.3, plus listed versions 1.1.11.1.2	1.1.3

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, products	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2017-0256 is a medium vulnerability (CVSS 5.3) in Microsoft Asp.net Core, published May 12, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.54%, the 89th percentile. Fixed in Microsoft.AspNetCore.Mvc 1.0.4.

Attack profile

How easy it is to exploit

What an attacker can affect

Exploit likelihood

What each source reports

Affected products

Affected packages

History

In short

References