Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability

Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service...

Allocation of Resources Without Limits or Throttling

Overview Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling. An attacker can exhaust system resources by sending specially crafted requests over the network, resulting in service unavailability for legitimate users. Remediation Upgrade...

Allocation of Resources Without Limits or Throttling

Overview Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling. An attacker can exhaust system resources by sending specially crafted requests over the network, resulting in service unavailability for legitimate users. Remediation Upgrade...

Symlink Attack

Overview Affected versions of this package are vulnerable to Symlink Attack via improper link resolution before file access. An attacker can modify local files by exploiting symbolic links to redirect file operations to unintended locations. Remediation Upgrade...

Symlink Attack

Overview Affected versions of this package are vulnerable to Symlink Attack via improper link resolution before file access. An attacker can modify local files by exploiting symbolic links to redirect file operations to unintended locations. Remediation Upgrade...

Infinite loop

Overview Microsoft.AspNetCore.App.Runtime.linux-musl-x64 is a package providing a default set of APIs for building an ASP.NET Core application. Contains assets used for self-contained deployments. Affected versions of this package are vulnerable to Infinite loop in the...

Infinite loop

Overview Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 is a package providing a default set of APIs for building an ASP.NET Core application. Contains assets used for self-contained deployments. Affected versions of this package are vulnerable to Infinite loop in the...

Infinite loop

Overview Microsoft.AspNetCore.App.Runtime.linux-musl-arm is a package providing a default set of APIs for building an ASP.NET Core application. Contains assets used for self-contained deployments. Affected versions of this package are vulnerable to Infinite loop in the...

HTTP Response Splitting

Overview Affected versions of this package are vulnerable to HTTP Response Splitting via the MailAddressParser.TryParseAddress function due to improper neutralisation of CRLF sequences. An attacker can impersonate another user or entity by sending specially crafted data over the network...

HTTP Response Splitting

Overview Affected versions of this package are vulnerable to HTTP Response Splitting via the MailAddressParser.TryParseAddress function due to improper neutralisation of CRLF sequences. An attacker can impersonate another user or entity by sending specially crafted data over the network...

HTTP Response Splitting

Overview Affected versions of this package are vulnerable to HTTP Response Splitting via the MailAddressParser.TryParseAddress function due to improper neutralisation of CRLF sequences. An attacker can impersonate another user or entity by sending specially crafted data over the network...

Allocation of Resources Without Limits or Throttling

Overview Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 is a package providing a default set of APIs for building an ASP.NET Core application. Contains assets used for self-contained deployments. Affected versions of this package are vulnerable to Allocation of Resources Without Limits or...

Out-of-bounds Read

Overview Affected versions of this package are vulnerable to Out-of-bounds Read when decoding malformed Base64Url input. An attacker can cause a disruption of service. Remediation Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to version 9.0.14, 10.0.4 or higher. References - GitHub Commit ...

Out-of-bounds Read

Overview Affected versions of this package are vulnerable to Out-of-bounds Read when decoding malformed Base64Url input. An attacker can cause a disruption of service. Remediation Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to version 9.0.14, 10.0.4 or higher. References - GitHub Commi...

Out-of-bounds Read

Overview Affected versions of this package are vulnerable to Out-of-bounds Read when decoding malformed Base64Url input. An attacker can cause a disruption of service. Remediation Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to version 9.0.14, 10.0.4 or higher. References - GitHub Commit ...

Incorrect Default Permissions

Overview Affected versions of this package are vulnerable to Incorrect Default Permissions. An attacker can gain elevated privileges by exploiting these permissions locally. Remediation Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to version 10.0.4 or higher. References - Vulnerability...

Incorrect Default Permissions

Overview Affected versions of this package are vulnerable to Incorrect Default Permissions. An attacker can gain elevated privileges by exploiting these permissions locally. Remediation Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to version 10.0.4 or higher. References - Vulnerability...

Inadequate Encryption Strength

Overview Affected versions of this package are vulnerable to Inadequate Encryption Strength via the SMTP process. An attacker can intercept sensitive information by performing a man-in-the-middle attack that prevents the use of TLS, causing data to be sent over an unencrypted connection...

HTTP Request Smuggling

Overview Microsoft.AspNetCore.App.Runtime.linux-musl-arm is a package providing a default set of APIs for building an ASP.NET Core application. Contains assets used for self-contained deployments. Affected versions of this package are vulnerable to HTTP Request Smuggling via the interpretation of...

HTTP Request Smuggling

Overview Microsoft.AspNetCore.App.Runtime.linux-musl-x64 is a package providing a default set of APIs for building an ASP.NET Core application. Contains assets used for self-contained deployments. Affected versions of this package are vulnerable to HTTP Request Smuggling via the interpretation of...