Auth bypass in Nextcloud Server
CVE-2026-45810
Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 31.0.0 to before 31.0.12, and 32.0.0 to before 32.0.3, a missing check of a relation allowed authenticated users with access to any file comment, to read the content of all comments. It is recommended that the Nextcloud Server is upgraded to 31.0.12 or 32.0.3. It is recommended that the Nextcloud Enterprise Server is upgraded to 21.0.9.20, 22.2.10.35, 23.0.12.31, 24.0.12.30, 25.0.13.25, 26.0.13.22, 27.1.11.22, 28.0.14.13, 29.0.16.10, 30.0.17.5, 31.0.12 or 32.0.3
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (35.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.4% 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: 0.004 · change: +0.002
Affected products
- Nextcloud Server
- Nextcloud Security-Advisories — versions >= 31.0.0, < 31.0.12, >= 32.0.0, < 32.0.3
Weakness classification (CWE)
References
- github.com/nextcloud/security-advisories/security/advisories/GHSA-285v-p9x9-cjhj (Vendor Advisory)
- github.com/nextcloud/server/pull/56982 (Patch, Issue Tracking)
- hackerone.com/reports/3425534 (Permissions Required)
Frequently asked questions
- What is CVE-2026-45810?
- CVE-2026-45810 is a medium-severity vulnerability in Nextcloud Server, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.8/10. Published 2026-06-01.
- How severe is CVE-2026-45810?
- Medium severity. CVSS v3 base score is 6.8 out of 10.