ownCloud Improper Authentication Vulnerability. Actively exploited: CISA added this vulnerability to its Known Exploited Vulnerabilities catalog on 27/08/2026. Patch affected systems as an emergency.
| Package | Affected versions | Patched versions |
|---|---|---|
| owncloud server | ≥ 10.6.0, < 10.13.1 | 10.13.1 |
An issue was discovered in ownCloud owncloud/core before 10.13.1. An attacker can access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured. This occurs because pre-signed URLs can be accepted even when no signing-key is configured for the owner of the files. The earliest affected version is 10.6.0.
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