Nextcloud · Nextcloud Server · CVE-2023-28643
**Name of the Vulnerable Software and Affected Versions**
Nextcloud Server versions prior to 24.0.9
Nextcloud Server versions prior to 25.0.3
**Description**
The issue is related to the handling of shared resources with the same name in Nextcloud Server, particularly when a memory cache is configured. If a recipient receives two shares with the same name, the second share will replace the first one instead of being renamed to `{name} (2)`. This can lead to a denial of service. The vulnerability can be exploited by a remote attacker to cause a collision of shared resources for recipients when caching is enabled.
**Recommendations**
For Nextcloud Server versions prior to 24.0.9, upgrade to version 24.0.9.
For Nextcloud Server versions prior to 25.0.3, upgrade to version 25.0.3.
As a temporary workaround for users unable to upgrade, avoid sharing two folders with the same name to the same user.