Zitadel is an open source identity management system. ZITADEL administrators can enable a setting called "Ignoring unknown usernames" which helps mitigate attacks that try to guess/enumerate usernames. If enabled, ZITADEL will show the password prompt even if the user doesn't exist and report "Username or Password invalid". Due to a implementation change to prevent deadlocks calling the database, the flag would not be correctly respected in all cases and an attacker would gain information if an account exist within ZITADEL, since the error message shows "object not found" instead of the generic error message. This vulnerability is fixed in 2.58.1, 2.57.1, 2.56.2, 2.55.5, 2.54.8, and 2.53.9.
https://github.com/zitadel/zitadel/security/advisories/GHSA-567v-6hmg-6qg7
https://github.com/zitadel/zitadel/releases/tag/v2.58.1
https://github.com/zitadel/zitadel/releases/tag/v2.57.1
https://github.com/zitadel/zitadel/releases/tag/v2.56.2
https://github.com/zitadel/zitadel/releases/tag/v2.55.5
https://github.com/zitadel/zitadel/releases/tag/v2.54.8
https://github.com/zitadel/zitadel/releases/tag/v2.53.9
https://github.com/zitadel/zitadel/commit/fc1d415b8db5b8d481bb65206ce3fc944c0eecea
https://github.com/zitadel/zitadel/commit/b0e71a81ef39667ce2a149ce037c1ca0edbe059d
https://github.com/zitadel/zitadel/commit/8565d24fd8df5bd35294313cfbfcc2e15aea20e9
https://github.com/zitadel/zitadel/commit/5c2526c98aafd1ba206be2fa4291b1d24c384f6d
https://github.com/zitadel/zitadel/commit/3c7d12834e32426416235b9e3374be0f4b9380b8
https://github.com/zitadel/zitadel/commit/0ab0c645ef914298c343fa39cccb1290aba48bf6