backport of commit 3aa5b91 (#25651)

Co-authored-by: Peter Wilson <peter.wilson@hashicorp.com>

website/content/docs/upgrading/upgrade-to-1.15.x.mdx

@@ -70,3 +70,5 @@ option.
 @include 'known-issues/1_15_audit-use-of-log-raw-applies-to-all-devices.mdx'
 
 @include 'known-issues/perf-secondary-many-mounts-deadlock.mdx'
+
+@include 'known-issues/1_15-audit-panic-handling-with-eventlogger.mdx'

website/content/partials/known-issues/1_15-audit-panic-handling-with-eventlogger.mdx

@@ -0,0 +1,24 @@
+### Audit fails to recover from panics when formatting audit entries
+
+#### Affected versions
+
+- 1.15.0 - 1.15.5
+
+#### Issue
+
+Due to an issue in the new event framework, Vault tries to resolve panics that
+occur when formatting audit entries. Vault cannot resolve the panic correctly,
+which results in the server terminating unexpectedly.
+
+The panic issue was resolved in `1.15.6`.
+
+#### Workaround
+
+Set the `VAULT_AUDIT_DISABLE_EVENTLOGGER` environment variable to `true` to
+disable the new underlying event framework and restart Vault:
+
+```shell-session
+$ export VAULT_AUDIT_DISABLE_EVENTLOGGER=true
+```
+
+On startup, Vault reverts to the audit behavior used in `1.14.x`.