# Which Problems Are Solved
Host headers used to identify the instance and further used in public responses such as OIDC discovery endpoints, email links and more were not correctly handled. While they were matched against existing instances, they were not properly sanitized.
# How the Problems Are Solved
Sanitize host header including port validation (if provided).
# Additional Changes
None
# Additional Context
- requires backports
(cherry picked from commit 72a5c33e6a)
7520450e11