Auth bypass in Nextcloud Security-Advisories
CVE-2025-66551
Nextcloud Tables allows you to create your own tables with individual columns. Prior to 0.8.6 and 0.9.3, a malicious user was able to create their own table and then move a column to a victims table. This vulnerability is fixed in 0.8.6 and 0.9.3.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:L.
EPSS exploit prediction
EPSS: 0.003 (15.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Nextcloud Security-Advisories — versions >= 0.9.0-beta.1, < 0.9.3, < 0.8.6
- Nextcloud Tables
Weakness classification (CWE)
References
- github.com/nextcloud/security-advisories/security/advisories/GHSA-w787-vwqp-8wr7 (Vendor Advisory)
- github.com/nextcloud/tables/pull/1810 (Patch, Issue Tracking)
- github.com/nextcloud/tables/commit/39f24a62fb41fd7a8bda65325f8bbafdc91c731c (Patch)
- hackerone.com/reports/3137895 (Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-66551?
- CVE-2025-66551 is a medium-severity vulnerability in Nextcloud Security-Advisories, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.3/10. Published 2025-12-05.
- How severe is CVE-2025-66551?
- Medium severity. CVSS v3 base score is 6.3 out of 10.