Repair broken links (#50710)

* Fix broken links.

* Address copilot comment.

* Update docs/fundamentals/runtime-libraries/system-security-cryptography-xml-signedxml.md

---------

Co-authored-by: Meaghan Osagie (Lewis) <[email protected]>

Author: TimShererWithAquent

docs/core/whats-new/dotnet-9/libraries.md

@@ -135,7 +135,7 @@ Those methods all used content-sniffing to figure out if the input was something
 
 ### OpenSSL providers support
 
-.NET 8 introduced the OpenSSL-specific APIs <xref:System.Security.Cryptography.SafeEvpPKeyHandle.OpenPrivateKeyFromEngine(System.String,System.String)> and <xref:System.Security.Cryptography.SafeEvpPKeyHandle.OpenPublicKeyFromEngine(System.String,System.String)>. They enable interacting with OpenSSL [`ENGINE` components](https://github.com/openssl/openssl/blob/master/README-ENGINES.md) and use hardware security modules (HSM), for example.
+.NET 8 introduced the OpenSSL-specific APIs <xref:System.Security.Cryptography.SafeEvpPKeyHandle.OpenPrivateKeyFromEngine(System.String,System.String)> and <xref:System.Security.Cryptography.SafeEvpPKeyHandle.OpenPublicKeyFromEngine(System.String,System.String)>. They enable interacting with OpenSSL `ENGINE` components and use hardware security modules (HSM), for example.
 
 .NET 9 introduces <xref:System.Security.Cryptography.SafeEvpPKeyHandle.OpenKeyFromProvider(System.String,System.String)?displayProperty=nameWithType>, which enables using [OpenSSL providers](https://docs.openssl.org/master/man7/provider/) and interacting with providers such as `tpm2` or `pkcs11`.
 

docs/fundamentals/runtime-libraries/system-security-cryptography-xml-signedxml.md

@@ -145,4 +145,4 @@ With the security updated introduced by the [Microsoft Security Bulletin MS16-03
 
 If an application does not verify that external references seem appropriate for the current context, they can be abused in ways that provide for many security vulnerabilities (including Denial of Service, Distributed Reflection Denial of Service, Information Disclosure, Signature Bypass, and Remote Code Execution). Even if an application were to validate the external reference URI, there would remain a problem of the resource being loaded twice: once when your application reads it, and once when <xref:System.Security.Cryptography.Xml.SignedXml> reads it. Since there's no guarantee that the application read and document verify steps have the same content, the signature does not provide trustworthiness.
 
-Given the risks of external references, <xref:System.Security.Cryptography.Xml.SignedXml> will throw an exception when an external reference is encountered. For more information about this issue, see [KB article 3148821](https://support.microsoft.com/kb/3148821).
+Given the risks of external references, <xref:System.Security.Cryptography.Xml.SignedXml> will throw an exception when an external reference is encountered. For more information about this issue, see [.NET Framework applications encounter exception errors](https://support.microsoft.com/topic/after-you-apply-security-update-3141780-net-framework-applications-encounter-exception-errors-or-unexpected-failures-while-processing-files-that-contain-signedxml-922edd45-a91e-c755-bb30-2604acf37362).