Add known issue notice for #18636.

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## 1.16.1 (August 8, 2023)
 
+KNOWN ISSUES:
+
+* connect: Consul versions 1.16.0 and 1.16.1 may have issues when a snapshot restore is performed and the servers are hosting xDS streams. When this bug triggers, it will cause Envoy to incorrectly populate upstream endpoints. This bug should be fixed in Consul 1.16.2 by [GH-18636](https://github.com/hashicorp/consul/pull/18636).
+
 SECURITY:
 
 * Update `golang.org/x/net` to v0.13.0 to address [CVE-2023-3978](https://nvd.nist.gov/vuln/detail/CVE-2023-3978). [[GH-18358](https://github.com/hashicorp/consul/issues/18358)]
@@ -136,6 +140,10 @@ https://github.com/rboyer/safeio/pull/3 [[GH-18302](https://github.com/hashicorp
 
 ## 1.16.0 (June 26, 2023)
 
+KNOWN ISSUES:
+
+* connect: Consul versions 1.16.0 and 1.16.1 may have issues when a snapshot restore is performed and the servers are hosting xDS streams. When this bug triggers, it will cause Envoy to incorrectly populate upstream endpoints. This bug should be fixed in Consul 1.16.2 by [GH-18636](https://github.com/hashicorp/consul/pull/18636).
+
 BREAKING CHANGES:
 
 * api: The `/v1/health/connect/` and `/v1/health/ingress/` endpoints now immediately return 403 "Permission Denied" errors whenever a token with insufficient `service:read` permissions is provided. Prior to this change, the endpoints returned a success code with an empty result list when a token with insufficient permissions was provided. [[GH-17424](https://github.com/hashicorp/consul/issues/17424)]

website/content/docs/release-notes/consul/v1_16_x.mdx

@@ -64,6 +64,16 @@ We are pleased to announce the following Consul updates.
 
 For more detailed information, please refer to the [upgrade details page](/consul/docs/upgrading/upgrade-specific) and the changelogs.
 
+## Known Issues
+
+The following issues are known to exist in the v1.16.x releases:
+
+- v1.16.0 - v1.16.1 may have issues when a snapshot restore is performed
+    and the servers are hosting xDS streams. When this bug triggers, it
+    will cause Envoy to incorrectly populate upstream endpoints. It is
+    currently not recommended for service mesh users to upgrade Consul to
+    these versions.
+
 ## Changelogs
 
 The changelogs for this major release version and any maintenance versions are listed below.

website/content/docs/upgrading/upgrade-specific.mdx

@@ -16,6 +16,12 @@ upgrade flow.
 
 ## Consul 1.16.x
 
+#### Known issues
+
+Service mesh in Consul versions 1.16.0 and 1.16.1 may have issues when a snapshot restore is performed and the servers are hosting xDS streams.
+When this bug triggers, it will cause Envoy to incorrectly populate upstream endpoints. Due to this issue, it is currently not recommended for
+service mesh users to upgrade Consul to these versions.
+
 #### API health endpoints return different status code
 
 Consul versions 1.16.0+ now return an error 403 "Permission denied" status