Update: After our 4.9.1 release yesterday, the symfony/yaml package had a security release today. There is a patched version with the updated yaml dependency: https://github.com/getkirby/kirby/releases/tag/4.9.2
🚨 Security
This is a backport of our security release for Kirby 5. For all details and vulnerabilities see: https://github.com/getkirby/kirby/releases/tag/5.4.1
We recommend all users upgrade to Kirby 5. If an upgrade is not possible, this security release is the alternative solution.