Nextcloud server is an open source, personal cloud implementation. In affected versions a malicious user could try to reset the password of another user and then brute force the 62^21 combinations for the password reset token. As of commit `704eb3aa` password reset attempts are now throttled. Note that 62^21 combinations would significant compute resources to brute force. None the less it is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4. There are no known workarounds for this vulnerability.
https://github.com/nextcloud/server/pull/36489/commits/704eb3aa6cecc0a646f5cca4290b595f493f9ed3
https://github.com/nextcloud/server/pull/36489
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-v243-x6jc-42mp